diff --git a/GPU/Directx9/FragmentShaderGeneratorHLSL.cpp b/GPU/Directx9/FragmentShaderGeneratorHLSL.cpp
index 4cbe2c50ff..a48f1d17e9 100644
--- a/GPU/Directx9/FragmentShaderGeneratorHLSL.cpp
+++ b/GPU/Directx9/FragmentShaderGeneratorHLSL.cpp
@@ -291,6 +291,11 @@ bool GenerateFragmentShaderHLSL(const FShaderID &id, char *buffer, ShaderLanguag
 			WRITE(p, "  float4 v = In.v_color0 %s;\n", secondary);
 		}
 
+		if (enableFog) {
+			WRITE(p, "  float fogCoef = clamp(In.v_fogdepth, 0.0, 1.0);\n");
+			WRITE(p, "  v = lerp(float4(u_fogcolor, v.a), v, fogCoef);\n");
+		}
+
 		if (enableAlphaTest) {
 			if (alphaTestAgainstZero) {
 				// When testing against 0 (extremely common), we can avoid some math.
@@ -322,11 +327,6 @@ bool GenerateFragmentShaderHLSL(const FShaderID &id, char *buffer, ShaderLanguag
 			}
 		}
 
-		if (enableFog) {
-			WRITE(p, "  float fogCoef = clamp(In.v_fogdepth, 0.0, 1.0);\n");
-			WRITE(p, "  v = lerp(float4(u_fogcolor, v.a), v, fogCoef);\n");
-		}
-
 		if (enableColorTest) {
 			if (colorTestAgainstZero) {
 				// When testing against 0 (common), we can avoid some math.
diff --git a/GPU/Vulkan/FragmentShaderGeneratorVulkan.cpp b/GPU/Vulkan/FragmentShaderGeneratorVulkan.cpp
index 29579a11e4..a726a8558a 100644
--- a/GPU/Vulkan/FragmentShaderGeneratorVulkan.cpp
+++ b/GPU/Vulkan/FragmentShaderGeneratorVulkan.cpp
@@ -352,6 +352,11 @@ bool GenerateFragmentShaderVulkanGLSL(const FShaderID &id, char *buffer, uint32_
 			WRITE(p, "  vec4 v = v_color0 %s;\n", secondary);
 		}
 
+		if (enableFog) {
+			WRITE(p, "  float fogCoef = clamp(v_fogdepth, 0.0, 1.0);\n");
+			WRITE(p, "  v = mix(vec4(u_fogcolor, v.a), v, fogCoef);\n");
+		}
+
 		// Texture access is at half texels [0.5/256, 255.5/256], but colors are normalized [0, 255].
 		// So we have to scale to account for the difference.
 		std::string alphaTestXCoord = "0";
@@ -374,7 +379,7 @@ bool GenerateFragmentShaderVulkanGLSL(const FShaderID &id, char *buffer, uint32_
 			} else {
 				const char *alphaTestFuncs[] = { "#", "#", " != ", " == ", " >= ", " > ", " <= ", " < " };
 				if (alphaTestFuncs[alphaTestFunc][0] != '#') {
-					WRITE(p, "  if ((roundAndScaleTo255i(v.a) & u_alphacolormask.a) %s u_alphacolorref.a) %s\n", alphaTestFuncs[alphaTestFunc], discardStatement);
+					WRITE(p, "  if ((roundAndScaleTo255i(v.a) & u_alphacolormask.a) %s int(u_alphacolorref.a)) %s\n", alphaTestFuncs[alphaTestFunc], discardStatement);
 				} else {
 					// This means NEVER.  See above.
 					WRITE(p, "  %s\n", discardStatement);
@@ -382,12 +387,6 @@ bool GenerateFragmentShaderVulkanGLSL(const FShaderID &id, char *buffer, uint32_
 			}
 		}
 
-		if (enableFog) {
-			WRITE(p, "  float fogCoef = clamp(v_fogdepth, 0.0, 1.0);\n");
-			WRITE(p, "  v = mix(vec4(u_fogcolor, v.a), v, fogCoef);\n");
-			// WRITE(p, "  v.x = v_depth;\n");
-		}
-
 		if (enableColorTest) {
 			if (colorTestAgainstZero) {
 				// When testing against 0 (common), we can avoid some math.
@@ -419,7 +418,7 @@ bool GenerateFragmentShaderVulkanGLSL(const FShaderID &id, char *buffer, uint32_
 		}
 
 		if (replaceBlend == REPLACE_BLEND_PRE_SRC || replaceBlend == REPLACE_BLEND_PRE_SRC_2X_ALPHA) {
-			const char *srcFactor = "ERROR";
+			const char *srcFactor = nullptr;
 			switch (replaceBlendFuncA) {
 			case GE_SRCBLEND_DSTCOLOR:          srcFactor = "ERROR"; break;
 			case GE_SRCBLEND_INVDSTCOLOR:       srcFactor = "ERROR"; break;
@@ -429,9 +428,12 @@ bool GenerateFragmentShaderVulkanGLSL(const FShaderID &id, char *buffer, uint32_
 			case GE_SRCBLEND_INVDSTALPHA:       srcFactor = "ERROR"; break;
 			case GE_SRCBLEND_DOUBLESRCALPHA:    srcFactor = "vec3(v.a * 2.0)"; break;
 			case GE_SRCBLEND_DOUBLEINVSRCALPHA: srcFactor = "vec3(1.0 - v.a * 2.0)"; break;
-			case GE_SRCBLEND_DOUBLEDSTALPHA:    srcFactor = "ERROR"; break;
+			// PRE_SRC for REPLACE_BLEND_PRE_SRC_2X_ALPHA means "double the src."
+			// It's close to the same, but clamping can still be an issue.
+			case GE_SRCBLEND_DOUBLEDSTALPHA:    srcFactor = "vec3(2.0)"; break;
 			case GE_SRCBLEND_DOUBLEINVDSTALPHA: srcFactor = "ERROR"; break;
 			case GE_SRCBLEND_FIXA:              srcFactor = "u_blendFixA"; break;
+			default:                            srcFactor = "u_blendFixA"; break;
 			}
 
 			if (!strcmp(srcFactor, "ERROR")) {
@@ -460,6 +462,7 @@ bool GenerateFragmentShaderVulkanGLSL(const FShaderID &id, char *buffer, uint32_
 			case GE_SRCBLEND_DOUBLEDSTALPHA:    srcFactor = "vec3(destColor.a * 2.0)"; break;
 			case GE_SRCBLEND_DOUBLEINVDSTALPHA: srcFactor = "vec3(1.0 - destColor.a * 2.0)"; break;
 			case GE_SRCBLEND_FIXA:              srcFactor = "u_blendFixA"; break;
+			default:                            srcFactor = "u_blendFixA"; break;
 			}
 			switch (replaceBlendFuncB) {
 			case GE_DSTBLEND_SRCCOLOR:          dstFactor = "v.rgb"; break;
@@ -473,6 +476,7 @@ bool GenerateFragmentShaderVulkanGLSL(const FShaderID &id, char *buffer, uint32_
 			case GE_DSTBLEND_DOUBLEDSTALPHA:    dstFactor = "vec3(destColor.a * 2.0)"; break;
 			case GE_DSTBLEND_DOUBLEINVDSTALPHA: dstFactor = "vec3(1.0 - destColor.a * 2.0)"; break;
 			case GE_DSTBLEND_FIXB:              dstFactor = "u_blendFixB"; break;
+			default:                            dstFactor = "u_blendFixB"; break;
 			}
 
 			switch (replaceBlendEq) {
@@ -494,6 +498,9 @@ bool GenerateFragmentShaderVulkanGLSL(const FShaderID &id, char *buffer, uint32_
 			case GE_BLENDMODE_ABSDIFF:
 				WRITE(p, "  v.rgb = abs(v.rgb - destColor.rgb);\n");
 				break;
+			default:
+				*errorString = "Bad replace blend eq";
+				return false;
 			}
 		}
 
diff --git a/unittest/TestShaderGenerators.cpp b/unittest/TestShaderGenerators.cpp
index cb28331bb0..7fea59c9bb 100644
--- a/unittest/TestShaderGenerators.cpp
+++ b/unittest/TestShaderGenerators.cpp
@@ -174,19 +174,21 @@ bool TestShaderGenerators() {
 		id.d[1] = top;
 
 		bool generateSuccess[numLanguages]{};
+		std::string genErrorString[numLanguages];
 
 		for (int j = 0; j < numLanguages; j++) {
-			std::string genErrorString;
-			generateSuccess[j] = GenerateFShader(id, buffer[j], languages[j], &genErrorString);
-			if (!genErrorString.empty()) {
-				printf("%s\n", genErrorString.c_str());
+			generateSuccess[j] = GenerateFShader(id, buffer[j], languages[j], &genErrorString[j]);
+			if (!genErrorString[j].empty()) {
+				printf("%s\n", genErrorString[j].c_str());
 			}
 			// We ignore the contents of the error string here, not even gonna try to compile if it errors.
 		}
 
 		// Temporary test: Compare GLSL-in-Vulkan-mode vs Vulkan
 		if (generateSuccess[0] != generateSuccess[1]) {
-			printf("mismatching success!\n");
+			printf("mismatching success! %s %s\n", genErrorString[0].c_str(), genErrorString[1].c_str());
+			printf("%s\n", buffer[0]);
+			printf("%s\n", buffer[1]);
 			return 1;
 		}
 		if (generateSuccess[0] && strcmp(buffer[0], buffer[1])) {