diff --git a/drivers/gles2/shaders/scene.glsl b/drivers/gles2/shaders/scene.glsl
index 9251e210804..3e64c92e96e 100644
--- a/drivers/gles2/shaders/scene.glsl
+++ b/drivers/gles2/shaders/scene.glsl
@@ -526,7 +526,7 @@ FRAGMENT_SHADER_CODE
 
 #if defined(ENABLE_NORMALMAP)
 	normalmap.xy = normalmap.xy * 2.0 - 1.0;
-	normalmap.z = sqrt(1.0 - dot(normalmap.xy, normalmap.xy));
+	normalmap.z = sqrt(max(0.0, 1.0 - dot(normalmap.xy, normalmap.xy)));
 
 	// normal = normalize(mix(normal_interp, tangent * normalmap.x + binormal * normalmap.y + normal * normalmap.z, normaldepth)) * side;
 	normal = normalmap;
diff --git a/drivers/gles3/shaders/scene.glsl b/drivers/gles3/shaders/scene.glsl
index dee8bcbc58b..2d6f42679f0 100644
--- a/drivers/gles3/shaders/scene.glsl
+++ b/drivers/gles3/shaders/scene.glsl
@@ -1700,7 +1700,7 @@ FRAGMENT_SHADER_CODE
 #if defined(ENABLE_NORMALMAP)
 
 	normalmap.xy=normalmap.xy*2.0-1.0;
-	normalmap.z=sqrt(1.0-dot(normalmap.xy,normalmap.xy)); //always ignore Z, as it can be RG packed, Z may be pos/neg, etc.
+	normalmap.z=sqrt(max(0.0, 1.0-dot(normalmap.xy,normalmap.xy))); //always ignore Z, as it can be RG packed, Z may be pos/neg, etc.
 
 	normal = normalize( mix(normal_interp,tangent * normalmap.x + binormal * normalmap.y + normal * normalmap.z,normaldepth) ) * side;