diff --git a/src/Magnum/GL/AbstractShaderProgram.h b/src/Magnum/GL/AbstractShaderProgram.h
index f72621eca..4bde9b65d 100644
--- a/src/Magnum/GL/AbstractShaderProgram.h
+++ b/src/Magnum/GL/AbstractShaderProgram.h
@@ -1699,7 +1699,7 @@ class MAGNUM_GL_EXPORT AbstractShaderProgram: public AbstractObject {
         static MAGNUM_GL_LOCAL void cleanLogImplementationAngle(std::string& message);
         #endif
 
-        static MAGNUM_GL_LOCAL void completionStatusImplementationFallback(GLuint, GLenum, GLint*);
+        static MAGNUM_GL_LOCAL APIENTRY void completionStatusImplementationFallback(GLuint, GLenum, GLint*);
 
         MAGNUM_GL_LOCAL static void use(GLuint id);
         void use();
diff --git a/src/Magnum/GL/Implementation/ShaderProgramState.h b/src/Magnum/GL/Implementation/ShaderProgramState.h
index e057e5aad..95001ea80 100644
--- a/src/Magnum/GL/Implementation/ShaderProgramState.h
+++ b/src/Magnum/GL/Implementation/ShaderProgramState.h
@@ -47,7 +47,9 @@ struct ShaderProgramState {
     void(AbstractShaderProgram::*transformFeedbackVaryingsImplementation)(Containers::ArrayView<const std::string>, AbstractShaderProgram::TransformFeedbackBufferMode);
     #endif
     void(*cleanLogImplementation)(std::string&);
-    void(*completionStatusImplementation)(GLuint, GLenum, GLint* value);
+    /* This is a direct pointer to a GL function, so needs a __stdcall on
+       Windows to compile properly on 32 bits */
+    void(APIENTRY *completionStatusImplementation)(GLuint, GLenum, GLint* value);
 
     #ifndef MAGNUM_TARGET_WEBGL
     void(APIENTRY *uniform1fvImplementation)(GLuint, GLint, GLsizei, const GLfloat*);
diff --git a/src/Magnum/GL/Implementation/ShaderState.h b/src/Magnum/GL/Implementation/ShaderState.h
index caddd741d..4d37c764d 100644
--- a/src/Magnum/GL/Implementation/ShaderState.h
+++ b/src/Magnum/GL/Implementation/ShaderState.h
@@ -53,7 +53,9 @@ struct ShaderState {
 
     void(Shader::*addSourceImplementation)(std::string);
     void(*cleanLogImplementation)(std::string&);
-    void(*completionStatusImplementation)(GLuint, GLenum, GLint* value);
+    /* This is a direct pointer to a GL function, so needs a __stdcall on
+       Windows to compile properly on 32 bits */
+    void(APIENTRY *completionStatusImplementation)(GLuint, GLenum, GLint* value);
 
     GLint maxVertexOutputComponents,
         maxFragmentInputComponents;
diff --git a/src/Magnum/GL/Shader.h b/src/Magnum/GL/Shader.h
index 045d822bd..0272c2599 100644
--- a/src/Magnum/GL/Shader.h
+++ b/src/Magnum/GL/Shader.h
@@ -680,7 +680,7 @@ class MAGNUM_GL_EXPORT Shader: public AbstractObject {
         static MAGNUM_GL_LOCAL void cleanLogImplementationIntelWindows(std::string& message);
         #endif
 
-        static MAGNUM_GL_LOCAL void completionStatusImplementationFallback(GLuint, GLenum, GLint*);
+        static MAGNUM_GL_LOCAL APIENTRY void completionStatusImplementationFallback(GLuint, GLenum, GLint*);
 
         Type _type;
         GLuint _id;
diff --git a/src/Magnum/Shaders/DistanceFieldVectorGL.cpp b/src/Magnum/Shaders/DistanceFieldVectorGL.cpp
index 91ebe3acf..6c627cf98 100644
--- a/src/Magnum/Shaders/DistanceFieldVectorGL.cpp
+++ b/src/Magnum/Shaders/DistanceFieldVectorGL.cpp
@@ -166,8 +166,6 @@ template<UnsignedInt dimensions> DistanceFieldVectorGL<dimensions>::DistanceFiel
     if (id() == 0) return;
 
     CORRADE_INTERNAL_ASSERT_OUTPUT(checkLink());
-    CORRADE_INTERNAL_ASSERT_OUTPUT(cs._vert.checkCompile());
-    CORRADE_INTERNAL_ASSERT_OUTPUT(cs._frag.checkCompile());
 
     const GL::Context& context = GL::Context::current();
     const GL::Version version = cs._version;
diff --git a/src/Magnum/Shaders/FlatGL.cpp b/src/Magnum/Shaders/FlatGL.cpp
index 11718dc63..645d7eade 100644
--- a/src/Magnum/Shaders/FlatGL.cpp
+++ b/src/Magnum/Shaders/FlatGL.cpp
@@ -241,8 +241,6 @@ template<UnsignedInt dimensions> FlatGL<dimensions>::FlatGL(CompileState&& cs):
     if (id() == 0) return;
 
     CORRADE_INTERNAL_ASSERT_OUTPUT(checkLink());
-    CORRADE_INTERNAL_ASSERT_OUTPUT(cs._vert.checkCompile());
-    CORRADE_INTERNAL_ASSERT_OUTPUT(cs._frag.checkCompile());
 
     const GL::Context& context = GL::Context::current();
     const GL::Version version = cs._version;
diff --git a/src/Magnum/Shaders/VectorGL.cpp b/src/Magnum/Shaders/VectorGL.cpp
index b52aee517..dd6ff2c07 100644
--- a/src/Magnum/Shaders/VectorGL.cpp
+++ b/src/Magnum/Shaders/VectorGL.cpp
@@ -168,8 +168,6 @@ template<UnsignedInt dimensions> VectorGL<dimensions>::VectorGL(CompileState&& c
     if (id() == 0) return;
 
     CORRADE_INTERNAL_ASSERT_OUTPUT(checkLink());
-    CORRADE_INTERNAL_ASSERT_OUTPUT(cs._vert.checkCompile());
-    CORRADE_INTERNAL_ASSERT_OUTPUT(cs._frag.checkCompile());
 
     const GL::Context& context = GL::Context::current();
     const GL::Version version = cs._version;
diff --git a/src/Magnum/Shaders/VertexColorGL.cpp b/src/Magnum/Shaders/VertexColorGL.cpp
index d796a8aaa..01af44cd1 100644
--- a/src/Magnum/Shaders/VertexColorGL.cpp
+++ b/src/Magnum/Shaders/VertexColorGL.cpp
@@ -146,8 +146,6 @@ template<UnsignedInt dimensions> VertexColorGL<dimensions>::VertexColorGL(Compil
     if (id() == 0) return;
 
     CORRADE_INTERNAL_ASSERT_OUTPUT(checkLink());
-    CORRADE_INTERNAL_ASSERT_OUTPUT(cs._vert.checkCompile());
-    CORRADE_INTERNAL_ASSERT_OUTPUT(cs._frag.checkCompile());
 
     const GL::Context& context = GL::Context::current();
     const GL::Version version = cs._version;
diff --git a/src/MagnumExternal/OpenGL/GL/flextGL.h b/src/MagnumExternal/OpenGL/GL/flextGL.h
index 626c8aff5..d11cc1880 100644
--- a/src/MagnumExternal/OpenGL/GL/flextGL.h
+++ b/src/MagnumExternal/OpenGL/GL/flextGL.h
@@ -1523,7 +1523,7 @@ typedef void (APIENTRY *GLDEBUGPROC)(GLenum source,GLenum type,GLuint id,GLenum
 
 /* GL_VERSION_4_5 */
 
-#define GL_CONTEXT_LOST 0x0507 
+#define GL_CONTEXT_LOST 0x0507
 #define GL_LOWER_LEFT 0x8CA1
 #define GL_UPPER_LEFT 0x8CA2
 #define GL_NEGATIVE_ONE_TO_ONE 0x935E