diff --git a/aegisub/src/agi_pre.h b/aegisub/src/agi_pre.h
index e4e185aa3..5e3a72cc4 100644
--- a/aegisub/src/agi_pre.h
+++ b/aegisub/src/agi_pre.h
@@ -80,7 +80,10 @@
 #include <iconv.h>
 #include <locale.h>
 #include <math.h>
+#ifdef _OPENMP
+// Not all compilers have <omp.h> (example: MSVC Express)
 #include <omp.h>
+#endif
 #include <stdint.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -232,4 +235,8 @@
 #undef _CRT_SECURE_NO_WARNINGS
 #endif
 
+///////////////////
+// Aegisub headers
+#include "include/aegisub/exception.h"
+
 #endif // C++
diff --git a/aegisub/src/ass_entry.cpp b/aegisub/src/ass_entry.cpp
index 69151bf13..2ec7315f3 100644
--- a/aegisub/src/ass_entry.cpp
+++ b/aegisub/src/ass_entry.cpp
@@ -39,6 +39,10 @@
 // Headers
 #include "config.h"
 
+#ifndef AGI_PRE
+#include "include/aegisub/exception.h"
+#endif
+
 #include "ass_attachment.h"
 #include "ass_dialogue.h"
 #include "ass_entry.h"