diff --git a/README.md b/README.md
index c65a694d47..ec6798cfbd 100644
--- a/README.md
+++ b/README.md
@@ -138,7 +138,11 @@ MultiplyExpression : CastExpression MultiplyOperator CastExpression | CastExpres
 
 MultiplyOperator : token(Star) | token(Slash) | token(Percent)
 
-CastExpression : PrimaryExpression token(as) Type | PrimaryExpression
+CastExpression : UnaryExpression token(as) Type | UnaryExpression
+
+UnaryExpression : UnaryOp PrimaryExpression | PrimaryExpression
+
+UnaryOp : token(Not) | token(Dash) | token(Tilde)
 
 PrimaryExpression : token(Number) | token(String) | token(Unreachable) | FnCall | GroupedExpression | Block
 
@@ -149,9 +153,11 @@ FnCall : token(Symbol) token(LParen) list(Expression, token(Comma)) token(RParen
 Directive : token(NumberSign) token(Symbol) token(LParen) token(String) token(RParen)
 ```
 
-### Binary Operator Precedence
+### Operator Precedence
 
 ```
+x()
+!x -x ~x
 as
 * / %
 + -
diff --git a/src/codegen.cpp b/src/codegen.cpp
index dd1f8a4722..4ecceaabdd 100644
--- a/src/codegen.cpp
+++ b/src/codegen.cpp
@@ -317,6 +317,7 @@ static void find_declarations(CodeGen *g, AstNode *node) {
         case NodeTypeAddExpr:
         case NodeTypeMultExpr:
         case NodeTypeCastExpr:
+        case NodeTypeUnaryExpr:
         case NodeTypePrimaryExpr:
         case NodeTypeGroupedExpr:
             zig_unreachable();
@@ -542,6 +543,9 @@ static void analyze_node(CodeGen *g, AstNode *node) {
         case NodeTypeCastExpr:
             zig_panic("TODO");
             break;
+        case NodeTypeUnaryExpr:
+            zig_panic("TODO");
+            break;
         case NodeTypePrimaryExpr:
             switch (node->data.primary_expr.type) {
                 case PrimaryExprTypeNumber:
@@ -740,10 +744,35 @@ static LLVMValueRef gen_primary_expr(CodeGen *g, AstNode *node) {
     zig_unreachable();
 }
 
+static LLVMValueRef gen_unary_expr(CodeGen *g, AstNode *node) {
+    assert(node->type == NodeTypeUnaryExpr);
+    assert(node->data.unary_expr.primary_expr);
+
+    LLVMValueRef expr = gen_expr(g, node->data.unary_expr.primary_expr);
+
+    switch (node->data.unary_expr.unary_op) {
+        case UnaryOpNegation:
+            add_debug_source_node(g, node);
+            return LLVMBuildNeg(g->builder, expr, "");
+        case UnaryOpBoolNot:
+            {
+                LLVMValueRef zero = LLVMConstNull(LLVMTypeOf(expr));
+                add_debug_source_node(g, node);
+                return LLVMBuildICmp(g->builder, LLVMIntEQ, expr, zero, "");
+            }
+        case UnaryOpBinNot:
+            add_debug_source_node(g, node);
+            return LLVMBuildNot(g->builder, expr, "");
+        case UnaryOpInvalid:
+            zig_unreachable();
+    }
+
+}
+
 static LLVMValueRef gen_cast_expr(CodeGen *g, AstNode *node) {
     assert(node->type == NodeTypeCastExpr);
 
-    LLVMValueRef expr = gen_primary_expr(g, node->data.cast_expr.primary_expr);
+    LLVMValueRef expr = gen_expr(g, node->data.cast_expr.unary_expr);
 
     if (!node->data.cast_expr.type)
         return expr;
@@ -997,6 +1026,8 @@ static LLVMValueRef gen_expr(CodeGen *g, AstNode *node) {
             return gen_bool_or_expr(g, node);
         case NodeTypeReturnExpr:
             return gen_return_expr(g, node);
+        case NodeTypeUnaryExpr:
+            return gen_unary_expr(g, node);
         case NodeTypeRoot:
         case NodeTypeRootExportDecl:
         case NodeTypeFnProto:
diff --git a/src/parser.cpp b/src/parser.cpp
index 07ade572f0..00a180dadc 100644
--- a/src/parser.cpp
+++ b/src/parser.cpp
@@ -10,6 +10,16 @@
 #include <stdarg.h>
 #include <stdio.h>
 
+static const char *unary_op_str(UnaryOp unary_op) {
+    switch (unary_op) {
+        case UnaryOpInvalid: return "(invalid)";
+        case UnaryOpNegation: return "-";
+        case UnaryOpBoolNot: return "!";
+        case UnaryOpBinNot: return "~";
+    }
+    zig_unreachable();
+}
+
 static const char *mult_op_str(MultOp mult_op) {
     switch (mult_op) {
         case MultOpInvalid: return "(invalid)";
@@ -116,6 +126,8 @@ const char *node_type_str(NodeType node_type) {
             return "PrimaryExpr";
         case NodeTypeGroupedExpr:
             return "GroupedExpr";
+        case NodeTypeUnaryExpr:
+            return "UnaryExpr";
     }
     zig_unreachable();
 }
@@ -284,10 +296,15 @@ void ast_print(AstNode *node, int indent) {
             break;
         case NodeTypeCastExpr:
             fprintf(stderr, "%s\n", node_type_str(node->type));
-            ast_print(node->data.cast_expr.primary_expr, indent + 2);
+            ast_print(node->data.cast_expr.unary_expr, indent + 2);
             if (node->data.cast_expr.type)
                 ast_print(node->data.cast_expr.type, indent + 2);
             break;
+        case NodeTypeUnaryExpr:
+            fprintf(stderr, "%s %s\n", node_type_str(node->type),
+                    unary_op_str(node->data.unary_expr.unary_op));
+            ast_print(node->data.unary_expr.primary_expr, indent + 2);
+            break;
         case NodeTypePrimaryExpr:
             switch (node->data.primary_expr.type) {
                 case PrimaryExprTypeNumber:
@@ -688,21 +705,65 @@ static AstNode *ast_parse_primary_expr(ParseContext *pc, int *token_index, bool
     ast_invalid_token_error(pc, token);
 }
 
+static UnaryOp tok_to_unary_op(Token *token) {
+    switch (token->id) {
+        case TokenIdBang: return UnaryOpBoolNot;
+        case TokenIdDash: return UnaryOpNegation;
+        case TokenIdTilde: return UnaryOpBinNot;
+        default: return UnaryOpInvalid;
+    }
+}
+
 /*
-CastExpression : PrimaryExpression token(As) Type | PrimaryExpression
+UnaryOp : token(Not) | token(Dash) | token(Tilde)
+*/
+static UnaryOp ast_parse_unary_op(ParseContext *pc, int *token_index, bool mandatory) {
+    Token *token = &pc->tokens->at(*token_index);
+    UnaryOp result = tok_to_unary_op(token);
+    if (result == UnaryOpInvalid) {
+        if (mandatory) {
+            ast_invalid_token_error(pc, token);
+        } else {
+            return UnaryOpInvalid;
+        }
+    }
+    *token_index += 1;
+    return result;
+}
+
+/*
+UnaryExpression : UnaryOp PrimaryExpression | PrimaryExpression
+*/
+static AstNode *ast_parse_unary_expr(ParseContext *pc, int *token_index, bool mandatory) {
+    Token *token = &pc->tokens->at(*token_index);
+    UnaryOp unary_op = ast_parse_unary_op(pc, token_index, false);
+    if (unary_op == UnaryOpInvalid)
+        return ast_parse_primary_expr(pc, token_index, mandatory);
+
+    AstNode *primary_expr = ast_parse_primary_expr(pc, token_index, true);
+    AstNode *node = ast_create_node(NodeTypeUnaryExpr, token);
+    node->data.unary_expr.primary_expr = primary_expr;
+    node->data.unary_expr.unary_op = unary_op;
+
+    return node;
+}
+
+
+/*
+CastExpression : UnaryExpression token(as) Type | UnaryExpression
 */
 static AstNode *ast_parse_cast_expression(ParseContext *pc, int *token_index, bool mandatory) {
-    AstNode *primary_expr = ast_parse_primary_expr(pc, token_index, mandatory);
-    if (!primary_expr)
+    AstNode *unary_expr = ast_parse_unary_expr(pc, token_index, mandatory);
+    if (!unary_expr)
         return nullptr;
 
     Token *as_kw = &pc->tokens->at(*token_index);
     if (as_kw->id != TokenIdKeywordAs)
-        return primary_expr;
+        return unary_expr;
     *token_index += 1;
 
     AstNode *node = ast_create_node(NodeTypeCastExpr, as_kw);
-    node->data.cast_expr.primary_expr = primary_expr;
+    node->data.cast_expr.unary_expr = unary_expr;
 
     node->data.cast_expr.type = ast_parse_type(pc, *token_index, token_index);
 
diff --git a/src/parser.hpp b/src/parser.hpp
index 626152a973..da933c6dd4 100644
--- a/src/parser.hpp
+++ b/src/parser.hpp
@@ -40,6 +40,7 @@ enum NodeType {
     NodeTypeCastExpr,
     NodeTypePrimaryExpr,
     NodeTypeGroupedExpr,
+    NodeTypeUnaryExpr,
 };
 
 struct AstNodeRoot {
@@ -204,7 +205,7 @@ struct AstNodeMultExpr {
 };
 
 struct AstNodeCastExpr {
-    AstNode *primary_expr;
+    AstNode *unary_expr;
     // if type is non-null, do cast, otherwise nothing
     AstNode *type;
 };
@@ -233,6 +234,18 @@ struct AstNodeGroupedExpr {
     AstNode *expr;
 };
 
+enum UnaryOp {
+    UnaryOpInvalid,
+    UnaryOpBoolNot,
+    UnaryOpBinNot,
+    UnaryOpNegation,
+};
+
+struct AstNodeUnaryExpr {
+    UnaryOp unary_op;
+    AstNode *primary_expr;
+};
+
 struct AstNode {
     enum NodeType type;
     AstNode *parent;
@@ -264,6 +277,7 @@ struct AstNode {
         AstNodeCastExpr cast_expr;
         AstNodePrimaryExpr primary_expr;
         AstNodeGroupedExpr grouped_expr;
+        AstNodeUnaryExpr unary_expr;
     } data;
 };
 
diff --git a/src/tokenizer.cpp b/src/tokenizer.cpp
index 1852dbf142..3cfab3288a 100644
--- a/src/tokenizer.cpp
+++ b/src/tokenizer.cpp
@@ -249,6 +249,10 @@ ZigList<Token> *tokenize(Buf *buf) {
                         begin_token(&t, TokenIdPlus);
                         end_token(&t);
                         break;
+                    case '~':
+                        begin_token(&t, TokenIdTilde);
+                        end_token(&t);
+                        break;
                     case '-':
                         begin_token(&t, TokenIdDash);
                         t.state = TokenizeStateSawDash;
@@ -278,7 +282,7 @@ ZigList<Token> *tokenize(Buf *buf) {
                         t.state = TokenizeStateEq;
                         break;
                     case '!':
-                        begin_token(&t, TokenIdNot);
+                        begin_token(&t, TokenIdBang);
                         t.state = TokenizeStateBang;
                         break;
                     case '<':
@@ -578,7 +582,8 @@ static const char * token_name(Token *token) {
         case TokenIdBoolOr: return "BoolOr";
         case TokenIdBoolAnd: return "BoolAnd";
         case TokenIdEq: return "Eq";
-        case TokenIdNot: return "Not";
+        case TokenIdBang: return "Bang";
+        case TokenIdTilde: return "Tilde";
         case TokenIdCmpEq: return "CmpEq";
         case TokenIdCmpNotEq: return "CmpNotEq";
         case TokenIdCmpLessThan: return "CmpLessThan";
diff --git a/src/tokenizer.hpp b/src/tokenizer.hpp
index 725429a18e..2c9ad61957 100644
--- a/src/tokenizer.hpp
+++ b/src/tokenizer.hpp
@@ -43,7 +43,8 @@ enum TokenId {
     TokenIdBinXor,
     TokenIdEq,
     TokenIdCmpEq,
-    TokenIdNot,
+    TokenIdBang,
+    TokenIdTilde,
     TokenIdCmpNotEq,
     TokenIdCmpLessThan,
     TokenIdCmpGreaterThan,