diff --git a/include/epoxy/common.h b/include/epoxy/common.h
index 902f9b2..cf58ab2 100644
--- a/include/epoxy/common.h
+++ b/include/epoxy/common.h
@@ -53,4 +53,11 @@ typedef unsigned char bool;
 # include <stdbool.h>
 #endif
 
+EPOXY_BEGIN_DECLS
+
+EPOXY_PUBLIC bool epoxy_extension_in_string(const char *extension_list,
+                                            const char *ext);
+
+EPOXY_END_DECLS
+
 #endif /* EPOXY_COMMON_H */
diff --git a/src/dispatch_common.c b/src/dispatch_common.c
index 87bd98a..e2e62f7 100644
--- a/src/dispatch_common.c
+++ b/src/dispatch_common.c
@@ -446,6 +446,24 @@ epoxy_conservative_gl_version(void)
     return epoxy_internal_gl_version(100);
 }
 
+/**
+ * @brief Checks for the presence of an extension in an OpenGL extension string
+ *
+ * @param extension_list The string containing the list of extensions to check
+ * @param ext The name of the GL extension
+ * @return `true` if the extension is available'
+ *
+ * @note If you are looking to check whether a normal GL, EGL or GLX extension
+ * is supported by the client, this probably isn't the function you want.
+ *
+ * Some parts of the spec for OpenGL and friends will return an OpenGL formatted
+ * extension string that is seperate from the usual extension strings for the
+ * spec. This function provides easy parsing of those strings.
+ *
+ * @see epoxy_has_gl_extension()
+ * @see epoxy_has_egl_extension()
+ * @see epoxy_has_glx_extension()
+ */
 bool
 epoxy_extension_in_string(const char *extension_list, const char *ext)
 {
diff --git a/src/dispatch_common.h b/src/dispatch_common.h
index e16771f..9982567 100644
--- a/src/dispatch_common.h
+++ b/src/dispatch_common.h
@@ -165,8 +165,6 @@ bool epoxy_conservative_has_wgl_extension(const char *name);
 void *epoxy_conservative_egl_dlsym(const char *name, bool exit_if_fails);
 void *epoxy_conservative_glx_dlsym(const char *name, bool exit_if_fails);
 
-bool epoxy_extension_in_string(const char *extension_list, const char *ext);
-
 #define glBegin_unwrapped epoxy_glBegin_unwrapped
 #define glEnd_unwrapped epoxy_glEnd_unwrapped
 extern void UNWRAPPED_PROTO(glBegin_unwrapped)(GLenum primtype);