diff --git a/lib/std/math/ceil.zig b/lib/std/math/ceil.zig
index fbac256166..cf3adcf5b5 100644
--- a/lib/std/math/ceil.zig
+++ b/lib/std/math/ceil.zig
@@ -20,6 +20,10 @@ pub fn ceil(x: anytype) @TypeOf(x) {
         f32 => ceil32(x),
         f64 => ceil64(x),
         f128 => ceil128(x),
+
+        // TODO this is not correct for some targets
+        c_longdouble => @floatCast(c_longdouble, ceil128(x)),
+
         else => @compileError("ceil not implemented for " ++ @typeName(T)),
     };
 }
diff --git a/lib/std/math/floor.zig b/lib/std/math/floor.zig
index c5ddb9e144..d6761ba77e 100644
--- a/lib/std/math/floor.zig
+++ b/lib/std/math/floor.zig
@@ -21,6 +21,10 @@ pub fn floor(x: anytype) @TypeOf(x) {
         f32 => floor32(x),
         f64 => floor64(x),
         f128 => floor128(x),
+
+        // TODO this is not correct for some targets
+        c_longdouble => @floatCast(c_longdouble, floor128(x)),
+
         else => @compileError("floor not implemented for " ++ @typeName(T)),
     };
 }
diff --git a/lib/std/special/c_stage1.zig b/lib/std/special/c_stage1.zig
index cd2d833c2d..c0323b1ae7 100644
--- a/lib/std/special/c_stage1.zig
+++ b/lib/std/special/c_stage1.zig
@@ -644,32 +644,41 @@ export fn fmod(x: f64, y: f64) f64 {
 export fn floorf(x: f32) f32 {
     return math.floor(x);
 }
+export fn floor(x: f64) f64 {
+    return math.floor(x);
+}
+export fn floorl(x: c_longdouble) c_longdouble {
+    if (!long_double_is_f128) {
+        @panic("TODO implement this");
+    }
+    return math.floor(x);
+}
 
 export fn ceilf(x: f32) f32 {
     return math.ceil(x);
 }
-
-export fn floor(x: f64) f64 {
-    return math.floor(x);
-}
-
 export fn ceil(x: f64) f64 {
     return math.ceil(x);
 }
-
-export fn fmal(a: c_longdouble, b: c_longdouble, c: c_longdouble) c_longdouble {
+export fn ceill(x: c_longdouble) c_longdouble {
     if (!long_double_is_f128) {
         @panic("TODO implement this");
     }
-    return math.fma(c_longdouble, a, b, c);
+    return math.ceil(x);
+}
+
+export fn fmaf(a: f32, b: f32, c: f32) f32 {
+    return math.fma(f32, a, b, c);
 }
 
 export fn fma(a: f64, b: f64, c: f64) f64 {
     return math.fma(f64, a, b, c);
 }
-
-export fn fmaf(a: f32, b: f32, c: f32) f32 {
-    return math.fma(f32, a, b, c);
+export fn fmal(a: c_longdouble, b: c_longdouble, c: c_longdouble) c_longdouble {
+    if (!long_double_is_f128) {
+        @panic("TODO implement this");
+    }
+    return math.fma(c_longdouble, a, b, c);
 }
 
 export fn sin(a: f64) f64 {