diff --git a/lib/std/fs.zig b/lib/std/fs.zig
index fe59b6ee2e..ec351ff6e2 100644
--- a/lib/std/fs.zig
+++ b/lib/std/fs.zig
@@ -810,7 +810,7 @@ pub const Dir = struct {
         };
         var attr = w.OBJECT_ATTRIBUTES{
             .Length = @sizeOf(w.OBJECT_ATTRIBUTES),
-            .RootDirectory = if (path.isAbsoluteW(sub_path_w)) null else self.fd,
+            .RootDirectory = if (path.isAbsoluteWindowsW(sub_path_w)) null else self.fd,
             .Attributes = 0, // Note we do not use OBJ_CASE_INSENSITIVE here.
             .ObjectName = &nt_name,
             .SecurityDescriptor = null,
@@ -960,7 +960,7 @@ pub const Dir = struct {
         };
         var attr = w.OBJECT_ATTRIBUTES{
             .Length = @sizeOf(w.OBJECT_ATTRIBUTES),
-            .RootDirectory = if (path.isAbsoluteW(sub_path_w)) null else self.fd,
+            .RootDirectory = if (path.isAbsoluteWindowsW(sub_path_w)) null else self.fd,
             .Attributes = 0, // Note we do not use OBJ_CASE_INSENSITIVE here.
             .ObjectName = &nt_name,
             .SecurityDescriptor = null,
@@ -1327,7 +1327,7 @@ pub fn openFileAbsoluteC(absolute_path_c: [*:0]const u8, flags: File.OpenFlags)
 
 /// Same as `openFileAbsolute` but the path parameter is WTF-16 encoded.
 pub fn openFileAbsoluteW(absolute_path_w: [*:0]const u16, flags: File.OpenFlags) File.OpenError!File {
-    assert(path.isAbsoluteW(absolute_path_w));
+    assert(path.isAbsoluteWindowsW(absolute_path_w));
     return cwd().openFileW(absolute_path_w, flags);
 }
 
@@ -1350,7 +1350,7 @@ pub fn createFileAbsoluteC(absolute_path_c: [*:0]const u8, flags: File.CreateFla
 
 /// Same as `createFileAbsolute` but the path parameter is WTF-16 encoded.
 pub fn createFileAbsoluteW(absolute_path_w: [*:0]const u16, flags: File.CreateFlags) File.OpenError!File {
-    assert(path.isAbsoluteW(absolute_path_w));
+    assert(path.isAbsoluteWindowsW(absolute_path_w));
     return cwd().createFileW(absolute_path_w, flags);
 }
 
@@ -1371,7 +1371,7 @@ pub fn deleteFileAbsoluteC(absolute_path_c: [*:0]const u8) DeleteFileError!void
 
 /// Same as `deleteFileAbsolute` except the parameter is WTF-16 encoded.
 pub fn deleteFileAbsoluteW(absolute_path_w: [*:0]const u16) DeleteFileError!void {
-    assert(path.isAbsoluteW(absolute_path_w));
+    assert(path.isAbsoluteWindowsW(absolute_path_w));
     return cwd().deleteFileW(absolute_path_w);
 }
 
diff --git a/lib/std/fs/path.zig b/lib/std/fs/path.zig
index 2286df0470..f6f34585be 100644
--- a/lib/std/fs/path.zig
+++ b/lib/std/fs/path.zig
@@ -173,7 +173,7 @@ pub fn isAbsoluteWindows(path: []const u8) bool {
     return isAbsoluteWindowsImpl(u8, path);
 }
 
-pub fn isAbsoluteW(path_w: [*:0]const u16) bool {
+pub fn isAbsoluteWindowsW(path_w: [*:0]const u16) bool {
     return isAbsoluteWindowsImpl(u16, mem.toSliceConst(u16, path_w));
 }
 
diff --git a/lib/std/os/bits/linux.zig b/lib/std/os/bits/linux.zig
index e0fc5561f2..8077d4b16a 100644
--- a/lib/std/os/bits/linux.zig
+++ b/lib/std/os/bits/linux.zig
@@ -1572,7 +1572,7 @@ pub const NOFLSH = 128;
 pub const TOSTOP = 256;
 pub const IEXTEN = 32768;
 
-pub const TCSA = extern enum(usize) {
+pub const TCSA = extern enum(c_uint) {
     NOW,
     DRAIN,
     FLUSH,
diff --git a/src/ir.cpp b/src/ir.cpp
index ef3426d111..0687d18ef2 100644
--- a/src/ir.cpp
+++ b/src/ir.cpp
@@ -11864,7 +11864,7 @@ static ConstCastOnly types_match_const_cast_only(IrAnalyze *ira, ZigType *wanted
         }
         assert(wanted_type->data.fn.is_generic ||
                 wanted_type->data.fn.fn_type_id.next_param_index  == wanted_type->data.fn.fn_type_id.param_count);
-        for (size_t i = 0; i < wanted_type->data.fn.fn_type_id.next_param_index; i += 1) {
+        for (size_t i = 0; i < wanted_type->data.fn.fn_type_id.param_count; i += 1) {
             // note it's reversed for parameters
             FnTypeParamInfo *actual_param_info = &actual_type->data.fn.fn_type_id.param_info[i];
             FnTypeParamInfo *expected_param_info = &wanted_type->data.fn.fn_type_id.param_info[i];
@@ -30285,7 +30285,7 @@ static ZigType *ir_resolve_lazy_fn_type(IrAnalyze *ira, AstNode *source_node, La
         if (param_is_var_args) {
             if (fn_type_id.cc == CallingConventionC) {
                 fn_type_id.param_count = fn_type_id.next_param_index;
-                continue;
+                break;
             } else if (fn_type_id.cc == CallingConventionUnspecified) {
                 return get_generic_fn_type(ira->codegen, &fn_type_id);
             } else {
diff --git a/src/parser.cpp b/src/parser.cpp
index a4dc324b2f..0da7aac639 100644
--- a/src/parser.cpp
+++ b/src/parser.cpp
@@ -806,7 +806,7 @@ static AstNode *ast_parse_fn_proto(ParseContext *pc) {
         if (param_decl->data.param_decl.is_var_args)
             res->data.fn_proto.is_var_args = true;
         if (i != params.length - 1 && res->data.fn_proto.is_var_args)
-            ast_error(pc, first, "Function prototype have varargs as a none last paramter.");
+            ast_error(pc, first, "Function prototype have varargs as a none last parameter.");
     }
     return res;
 }
diff --git a/test/compile_errors.zig b/test/compile_errors.zig
index 341062e161..0af07d3ece 100644
--- a/test/compile_errors.zig
+++ b/test/compile_errors.zig
@@ -3,6 +3,17 @@ const builtin = @import("builtin");
 const Target = @import("std").Target;
 
 pub fn addCases(cases: *tests.CompileErrorContext) void {
+    cases.addTest("type mismatch in C prototype with varargs",
+        \\const fn_ty = ?fn ([*c]u8, ...) callconv(.C) void;
+        \\extern fn fn_decl(fmt: [*:0]u8, ...) void;
+        \\
+        \\export fn main() void {
+        \\    const x: fn_ty = fn_decl;
+        \\}
+    , &[_][]const u8{
+        "tmp.zig:5:22: error: expected type 'fn([*c]u8, ...) callconv(.C) void', found 'fn([*:0]u8, ...) callconv(.C) void'",
+    });
+
     cases.addTest("dependency loop in top-level decl with @TypeInfo",
         \\export const foo = @typeInfo(@This());
     , &[_][]const u8{