diff --git a/renderdoc/driver/gl/gl_common.cpp b/renderdoc/driver/gl/gl_common.cpp
index 5147a8796..b042a9bc5 100644
--- a/renderdoc/driver/gl/gl_common.cpp
+++ b/renderdoc/driver/gl/gl_common.cpp
@@ -458,7 +458,7 @@ ResourceFormat MakeResourceFormat(WrappedOpenGL &gl, GLenum target, GLenum fmt)
 	ret.strname = ToStr::Get(fmt).substr(3); // 3 == strlen("GL_")
 
 	// special handling for formats that don't query neatly
-	if(fmt == eGL_LUMINANCE8_EXT)
+	if(fmt == eGL_LUMINANCE8_EXT || fmt == eGL_INTENSITY8_EXT || fmt == eGL_ALPHA8_EXT)
 	{
 		ret.compByteWidth = 1;
 		ret.compCount = 1;
diff --git a/renderdoc/driver/gl/gl_resources.cpp b/renderdoc/driver/gl/gl_resources.cpp
index fa7190a0e..cf70f8b8f 100644
--- a/renderdoc/driver/gl/gl_resources.cpp
+++ b/renderdoc/driver/gl/gl_resources.cpp
@@ -25,10 +25,6 @@
 #include "gl_hookset.h"
 #include "gl_resources.h"
 
-// no longer in glcorearb.h or glext.h
-const GLenum eGL_LUMINANCE = (GLenum)0x1909;
-const GLenum eGL_LUMINANCE_ALPHA = (GLenum)0x190A;
-
 size_t GetByteSize(GLsizei w, GLsizei h, GLsizei d, GLenum format, GLenum type)
 {
 	size_t elemSize = 0;
@@ -95,6 +91,7 @@ size_t GetByteSize(GLsizei w, GLsizei h, GLsizei d, GLenum format, GLenum type)
 		case eGL_BLUE:
 		case eGL_BLUE_INTEGER:
 		case eGL_LUMINANCE:
+		case eGL_ALPHA:
 		case eGL_DEPTH_COMPONENT:
 		case eGL_STENCIL_INDEX:
 			return w*h*d*elemSize;
@@ -134,6 +131,8 @@ GLenum GetBaseFormat(GLenum internalFormat)
 		case eGL_R16F:
 		case eGL_R32F:
 			return eGL_RED;
+		case eGL_ALPHA8_EXT:
+			return eGL_ALPHA;
 		case eGL_R8I:
 		case eGL_R16I:
 		case eGL_R32I:
@@ -313,6 +312,8 @@ GLenum GetDataType(GLenum internalFormat)
 			return eGL_FLOAT_32_UNSIGNED_INT_24_8_REV;
 		case eGL_STENCIL_INDEX8:
 			return eGL_UNSIGNED_BYTE;
+		case eGL_ALPHA8_EXT:
+			return eGL_UNSIGNED_BYTE;
 		default:
 			break;
 	}
@@ -445,40 +446,64 @@ void EmulateLuminanceFormat(const GLHookSet &gl, GLuint tex, GLenum target, GLen
 {
 	GLenum swizzle[] = { eGL_RED, eGL_GREEN, eGL_BLUE, eGL_ALPHA };
 
-	bool dataFormatLum = (dataFormat == eGL_LUMINANCE || dataFormat == eGL_LUMINANCE_ALPHA);
+	bool dataFormatLum = (dataFormat == eGL_LUMINANCE || dataFormat == eGL_LUMINANCE_ALPHA || dataFormat == eGL_ALPHA || dataFormat == eGL_INTENSITY);
 
 	switch((int)internalFormat)
 	{
+		case eGL_INTENSITY:
+		case eGL_INTENSITY8_EXT:
+			internalFormat = eGL_R8;
+			if(dataFormatLum) dataFormat = eGL_RED;
+			swizzle[0] = swizzle[1] = swizzle[2] = swizzle[3] = eGL_RED; // intensity replicates across all 4 of RGBA
+			break;
+		case eGL_INTENSITY16_EXT:
+			internalFormat = eGL_R16;
+			if(dataFormatLum) dataFormat = eGL_RED;
+			swizzle[0] = swizzle[1] = swizzle[2] = swizzle[3] = eGL_RED; // intensity replicates across all 4 of RGBA
+			break;
+		case eGL_ALPHA:
+		case eGL_ALPHA8_EXT:
+			internalFormat = eGL_R8;
+			if(dataFormatLum) dataFormat = eGL_RED;
+			swizzle[0] = swizzle[1] = swizzle[2] = eGL_NONE;
+			swizzle[3] = eGL_RED; // single component alpha channel
+			break;
 		case eGL_LUMINANCE:
 		case eGL_LUMINANCE8_EXT:
 			internalFormat = eGL_R8;
 			if(dataFormatLum) dataFormat = eGL_RED;
 			swizzle[0] = swizzle[1] = swizzle[2] = eGL_RED;
+			swizzle[3] = (GLenum)1; // alpha explicitly set to 1 in luminance formats
 			break;
 		case eGL_SLUMINANCE8_EXT:
 			internalFormat = eGL_SRGB8;
 			if(dataFormatLum) dataFormat = eGL_RED;
 			swizzle[0] = swizzle[1] = swizzle[2] = eGL_RED;
+			swizzle[3] = (GLenum)1; // alpha explicitly set to 1 in luminance formats
 			break;
 		case eGL_LUMINANCE16_EXT:
 			internalFormat = eGL_R16;
 			if(dataFormatLum) dataFormat = eGL_RED;
 			swizzle[0] = swizzle[1] = swizzle[2] = eGL_RED;
+			swizzle[3] = (GLenum)1; // alpha explicitly set to 1 in luminance formats
 			break;
 		case eGL_LUMINANCE32F_ARB:
 			internalFormat = eGL_R32F;
 			if(dataFormatLum) dataFormat = eGL_RED;
 			swizzle[0] = swizzle[1] = swizzle[2] = eGL_RED;
+			swizzle[3] = (GLenum)1; // alpha explicitly set to 1 in luminance formats
 			break;
 		case eGL_LUMINANCE32I_EXT:
 			internalFormat = eGL_R32I;
 			if(dataFormatLum) dataFormat = eGL_RED;
 			swizzle[0] = swizzle[1] = swizzle[2] = eGL_RED;
+			swizzle[3] = (GLenum)1; // alpha explicitly set to 1 in luminance formats
 			break;
 		case eGL_LUMINANCE32UI_EXT:
 			internalFormat = eGL_R32UI;
 			if(dataFormatLum) dataFormat = eGL_RED;
 			swizzle[0] = swizzle[1] = swizzle[2] = eGL_RED;
+			swizzle[3] = (GLenum)1; // alpha explicitly set to 1 in luminance formats
 			break;
 		case eGL_LUMINANCE_ALPHA:
 		case eGL_LUMINANCE8_ALPHA8_EXT:
diff --git a/renderdoc/driver/gl/gl_resources.h b/renderdoc/driver/gl/gl_resources.h
index 73292f5f3..ba1ab2a67 100644
--- a/renderdoc/driver/gl/gl_resources.h
+++ b/renderdoc/driver/gl/gl_resources.h
@@ -36,6 +36,11 @@ GLenum GetBaseFormat(GLenum internalFormat);
 GLenum GetDataType(GLenum internalFormat);
 GLenum GetSizedFormat(const GLHookSet &gl, GLenum target, GLenum internalFormat);
 
+// no longer in glcorearb.h or glext.h
+const GLenum eGL_LUMINANCE = (GLenum)0x1909;
+const GLenum eGL_LUMINANCE_ALPHA = (GLenum)0x190A;
+const GLenum eGL_INTENSITY = (GLenum)0x8049;
+
 void EmulateLuminanceFormat(const GLHookSet &gl, GLuint tex, GLenum target, GLenum &internalFormat, GLenum &dataFormat);
 
 int GetNumMips(const GLHookSet &gl, GLenum target, GLuint tex, GLuint w, GLuint h, GLuint d);
diff --git a/renderdoc/driver/gl/wrappers/gl_texture_funcs.cpp b/renderdoc/driver/gl/wrappers/gl_texture_funcs.cpp
index da90bf407..1e21a0584 100644
--- a/renderdoc/driver/gl/wrappers/gl_texture_funcs.cpp
+++ b/renderdoc/driver/gl/wrappers/gl_texture_funcs.cpp
@@ -4150,6 +4150,22 @@ bool WrappedOpenGL::Serialise_glTextureSubImage1DEXT(GLuint texture, GLenum targ
 	{
 		if(!UnpackBufBound && m_State == READING && m_CurEventID == 0)
 			m_Real.glBindBuffer(eGL_PIXEL_UNPACK_BUFFER, 0);
+		
+		if(Format == eGL_LUMINANCE)
+		{
+			Format = eGL_RED;
+		}
+		else if(Format == eGL_LUMINANCE_ALPHA)
+		{
+			Format = eGL_RG;
+		}
+		else if(Format == eGL_ALPHA)
+		{
+			// check if format was converted from alpha-only format to R8, and substitute
+			ResourceId liveId = GetResourceManager()->GetLiveID(id);
+			if(m_Textures[liveId].internalFormat == eGL_R8)
+				Format = eGL_RED;
+		}
 
 		m_Real.glTextureSubImage1DEXT(GetResourceManager()->GetLiveResource(id).name, Target, Level, xoff, Width, Format, Type, buf ? buf : (const void *)bufoffs);
 
@@ -4343,6 +4359,22 @@ bool WrappedOpenGL::Serialise_glTextureSubImage2DEXT(GLuint texture, GLenum targ
 	{
 		if(!UnpackBufBound && m_State == READING && m_CurEventID == 0)
 			m_Real.glBindBuffer(eGL_PIXEL_UNPACK_BUFFER, 0);
+		
+		if(Format == eGL_LUMINANCE)
+		{
+			Format = eGL_RED;
+		}
+		else if(Format == eGL_LUMINANCE_ALPHA)
+		{
+			Format = eGL_RG;
+		}
+		else if(Format == eGL_ALPHA)
+		{
+			// check if format was converted from alpha-only format to R8, and substitute
+			ResourceId liveId = GetResourceManager()->GetLiveID(id);
+			if(m_Textures[liveId].internalFormat == eGL_R8)
+				Format = eGL_RED;
+		}
 
 		m_Real.glTextureSubImage2DEXT(GetResourceManager()->GetLiveResource(id).name, Target, Level, xoff, yoff, Width, Height, Format, Type, buf ? buf : (const void *)bufoffs);
 
@@ -4538,6 +4570,22 @@ bool WrappedOpenGL::Serialise_glTextureSubImage3DEXT(GLuint texture, GLenum targ
 	{
 		if(!UnpackBufBound && m_State == READING && m_CurEventID == 0)
 			m_Real.glBindBuffer(eGL_PIXEL_UNPACK_BUFFER, 0);
+		
+		if(Format == eGL_LUMINANCE)
+		{
+			Format = eGL_RED;
+		}
+		else if(Format == eGL_LUMINANCE_ALPHA)
+		{
+			Format = eGL_RG;
+		}
+		else if(Format == eGL_ALPHA)
+		{
+			// check if format was converted from alpha-only format to R8, and substitute
+			ResourceId liveId = GetResourceManager()->GetLiveID(id);
+			if(m_Textures[liveId].internalFormat == eGL_R8)
+				Format = eGL_RED;
+		}
 
 		m_Real.glTextureSubImage3DEXT(GetResourceManager()->GetLiveResource(id).name, Target, Level, xoff, yoff, zoff, Width, Height, Depth, Format, Type, buf ? buf : (const void *)bufoffs);