diff --git a/src/doomdef.h b/src/doomdef.h
index 796221c9..d63c5038 100644
--- a/src/doomdef.h
+++ b/src/doomdef.h
@@ -410,6 +410,15 @@ INT32 I_GetKey(void);
 #define max(x, y) (((x) > (y)) ? (x) : (y))
 #endif
 
+// Floating point comparison epsilons from float.h
+#ifndef FLT_EPSILON
+#define FLT_EPSILON 1.1920928955078125e-7f
+#endif
+
+#ifndef DBL_EPSILON
+#define DBL_EPSILON 2.2204460492503131e-16
+#endif
+
 // An assert-type mechanism.
 #ifdef PARANOIA
 #define I_Assert(e) ((e) ? (void)0 : I_Error("assert failed: %s, file %s, line %d", #e, __FILE__, __LINE__))
diff --git a/src/r_data.c b/src/r_data.c
index e0b9a814..a21ba49a 100644
--- a/src/r_data.c
+++ b/src/r_data.c
@@ -1220,7 +1220,7 @@ INT32 R_CreateColormap(char *p1, char *p2, char *p3)
 			continue;
 		if (maskcolor == extra_colormaps[i].maskcolor
 			&& fadecolor == extra_colormaps[i].fadecolor
-			&& fabsf((float)(maskamt - extra_colormaps[i].maskamt)) < 1.0E-36f
+			&& fabs(maskamt - extra_colormaps[i].maskamt) < DBL_EPSILON
 			&& fadestart == extra_colormaps[i].fadestart
 			&& fadeend == extra_colormaps[i].fadeend
 			&& fog == extra_colormaps[i].fog)