diff --git a/src/arch/helperavx.h b/src/arch/helperavx.h
index 4e4f9960..a0d218d6 100644
--- a/src/arch/helperavx.h
+++ b/src/arch/helperavx.h
@@ -63,7 +63,7 @@ static int cpuSupportsAVX() {
 static int cpuSupportsFMA4() {
     int32_t reg[4];
     Sleef_x86CpuID(reg, 0x80000001, 0);
-    return (reg[3] & (1 << 16)) != 0;
+    return (reg[2] & (1 << 16)) != 0;
 }
 
 #if CONFIG == 4 && defined(__AVX__) && defined(__FMA4__)
diff --git a/src/libm/dispavx.c.org b/src/libm/dispavx.c.org
index cd38af6d..0f242b42 100644
--- a/src/libm/dispavx.c.org
+++ b/src/libm/dispavx.c.org
@@ -48,7 +48,7 @@ static int cpuSupportsFMA4() {
   if (ret == -1) {
     int32_t reg[4];
     Sleef_x86CpuID(reg, 0x80000001, 0);
-    ret = (reg[3] & (1 << 16)) != 0;
+    ret = (reg[2] & (1 << 16)) != 0;
   }
   return ret;
 }