diff --git a/cogl/cogl-fixed.c b/cogl/cogl-fixed.c
index e3476057b..7af659f22 100644
--- a/cogl/cogl-fixed.c
+++ b/cogl/cogl-fixed.c
@@ -629,7 +629,7 @@ cogl_fixed_sqrt (CoglFixed x)
 	/*
 	 * Find the highest bit set
 	 */
-#if defined (__arm__) && !defined(__ARM_ARCH_4T__)
+#if defined (__arm__) && !defined(__ARM_ARCH_4T__) && !defined(__thumb__)
 	/* This actually requires at least arm v5, but gcc does not seem
 	 * to set the architecture defines correctly, and it is I think
 	 * very unlikely that anyone will want to use clutter on anything
@@ -807,7 +807,7 @@ CoglFixed
 cogl_fixed_mul (CoglFixed a,
                 CoglFixed b)
 {
-#ifdef __arm__
+#ifdef __arm__ && !defined(__thumb__)
   /* This provides about 12% speedeup on the gcc -O2 optimised
    * C version
    *