diff --git a/src/s_sound.cpp b/src/s_sound.cpp
index 665f3f6d3..9cf986597 100644
--- a/src/s_sound.cpp
+++ b/src/s_sound.cpp
@@ -1811,7 +1811,7 @@ float S_GetRolloff(FRolloffInfo *rolloff, float distance, bool logarithmic)
 		}
 		else
 		{
-			return float((pow(10.f, volume) - 1.) / 9.);
+			return float((powf(10.f, volume) - 1.) / 9.);
 		}
 	}
 	else
diff --git a/src/sdl/i_main.cpp b/src/sdl/i_main.cpp
index 2f9d48337..37771d7be 100644
--- a/src/sdl/i_main.cpp
+++ b/src/sdl/i_main.cpp
@@ -57,6 +57,8 @@
 #include "g_level.h"
 #include "r_state.h"
 #include "cmdlib.h"
+#include "r_main.h"
+#include "doomstat.h"
 
 // MACROS ------------------------------------------------------------------
 
diff --git a/src/sdl/i_system.cpp b/src/sdl/i_system.cpp
index 9fb864142..78318b10b 100644
--- a/src/sdl/i_system.cpp
+++ b/src/sdl/i_system.cpp
@@ -40,6 +40,7 @@
 
 #include "SDL.h"
 #include "doomtype.h"
+#include "doomstat.h"
 #include "version.h"
 #include "doomdef.h"
 #include "cmdlib.h"
@@ -61,6 +62,9 @@
 #include "hardware.h"
 #include "gameconfigfile.h"
 
+#include "m_fixed.h"
+#include "g_level.h"
+
 EXTERN_CVAR (String, language)
 
 extern "C"
diff --git a/src/sdl/st_start.cpp b/src/sdl/st_start.cpp
index 7cb64ca92..81e50d23e 100644
--- a/src/sdl/st_start.cpp
+++ b/src/sdl/st_start.cpp
@@ -42,6 +42,7 @@
 #include "st_start.h"
 #include "doomdef.h"
 #include "i_system.h"
+#include "c_cvars.h"
 
 // MACROS ------------------------------------------------------------------