diff --git a/configure.in b/configure.in
index 05ac887..1051021 100644
--- a/configure.in
+++ b/configure.in
@@ -78,6 +78,15 @@ AC_SUBST(ASFLAGS)
 SDL_FLAGS=`sdl-config --libs`
 AC_SUBST(SDL_FLAGS)
 
+AC_MSG_CHECKING(for underscore prefix in names)
+AC_TRY_LINK(
+	[asm(".long _bar");
+	int bar;],
+	[],
+	AC_DEFINE(HAVE_SYM_PREFIX_UNDERSCORE, 1, [Define this if C symbols are prefixed with an underscore]) AC_MSG_RESULT(yes),
+	AC_MSG_RESULT(no)
+)
+
 AC_CONFIG_FILES([Makefile
 				 src/Makefile
 				 src/baseq2/Makefile
diff --git a/src/d_copy.S b/src/d_copy.S
index dbab4b4..1fc7aa8 100644
--- a/src/d_copy.S
+++ b/src/d_copy.S
@@ -3,6 +3,9 @@
 // x86 assembly-language screen copying code.
 //
 
+#ifdef HAVE_CONFIG_H
+# include "config.h"
+#endif
 #include "../src/qasm.h"
 
 	.data
diff --git a/src/d_polysa.S b/src/d_polysa.S
index 78bf00c..331d60c 100644
--- a/src/d_polysa.S
+++ b/src/d_polysa.S
@@ -3,6 +3,9 @@
 // x86 assembly-language polygon model drawing code
 //
 
+#ifdef HAVE_CONFIG_H
+# include "config.h"
+#endif
 #include "../src/qasm.h"
 #include "d_ifacea.h"
 
diff --git a/src/math.S b/src/math.S
index c6aaf12..e7f1dea 100644
--- a/src/math.S
+++ b/src/math.S
@@ -2,6 +2,9 @@
 // math.s
 // x86 assembly-language math routines.
 
+#ifdef HAVE_CONFIG_H
+# include "config.h"
+#endif
 #define GLQUAKE	1	// don't include unneeded defs
 #include "../src/qasm.h"
 
diff --git a/src/qasm.h b/src/qasm.h
index a3ae286..a84f8a8 100644
--- a/src/qasm.h
+++ b/src/qasm.h
@@ -20,10 +20,10 @@ Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 #ifndef __ASM_I386__
 #define __ASM_I386__
 
-#if defined ELF && !defined __OpenBSD__
-#define C(label) label
-#else
+#ifdef HAVE_SYM_PREFIX_UNDERSCORE
 #define C(label) _##label
+#else
+#define C(label) label
 #endif
 
 
diff --git a/src/r_aclipa.S b/src/r_aclipa.S
index d4db210..b1c406f 100644
--- a/src/r_aclipa.S
+++ b/src/r_aclipa.S
@@ -3,6 +3,9 @@
 // x86 assembly-language Alias model transform and project code.
 //
 
+#ifdef HAVE_CONFIG_H
+# include "config.h"
+#endif
 #include "../src/qasm.h"
 #include "d_ifacea.h"
 
diff --git a/src/r_draw16.S b/src/r_draw16.S
index d4ee01c..55716db 100644
--- a/src/r_draw16.S
+++ b/src/r_draw16.S
@@ -4,6 +4,9 @@
 // subdivision.
 //
 
+#ifdef HAVE_CONFIG_H
+# include "config.h"
+#endif
 #include "../src/qasm.h"
 #include "d_ifacea.h"
 
diff --git a/src/r_drawa.S b/src/r_drawa.S
index 0e81bac..1c58a30 100644
--- a/src/r_drawa.S
+++ b/src/r_drawa.S
@@ -3,6 +3,9 @@
 // x86 assembly-language edge clipping and emission code
 //
 
+#ifdef HAVE_CONFIG_H
+# include "config.h"
+#endif
 #include "../src/qasm.h"
 #include "d_ifacea.h"
 
diff --git a/src/r_edgea.S b/src/r_edgea.S
index 3d896da..0c128e8 100644
--- a/src/r_edgea.S
+++ b/src/r_edgea.S
@@ -3,6 +3,9 @@
 // x86 assembly-language edge-processing code.
 //
 
+#ifdef HAVE_CONFIG_H
+# include "config.h"
+#endif
 #include "../src/qasm.h"
 
 #if	id386
diff --git a/src/r_scana.S b/src/r_scana.S
index eb09861..7669416 100644
--- a/src/r_scana.S
+++ b/src/r_scana.S
@@ -3,6 +3,9 @@
 // x86 assembly-language turbulent texture mapping code
 //
 
+#ifdef HAVE_CONFIG_H
+# include "config.h"
+#endif
 #include "../src/qasm.h"
 #include "d_ifacea.h"
 
diff --git a/src/r_spr8.S b/src/r_spr8.S
index 4286931..4809c54 100644
--- a/src/r_spr8.S
+++ b/src/r_spr8.S
@@ -3,6 +3,9 @@
 // x86 assembly-language horizontal 8-bpp transparent span-drawing code.
 //
 
+#ifdef HAVE_CONFIG_H
+# include "config.h"
+#endif
 #include "../src/qasm.h"
 
 #if id386
diff --git a/src/r_surf8.S b/src/r_surf8.S
index 8daa2f0..8d43bac 100644
--- a/src/r_surf8.S
+++ b/src/r_surf8.S
@@ -3,6 +3,9 @@
 // x86 assembly-language 8 bpp surface block drawing code.
 //
 
+#ifdef HAVE_CONFIG_H
+# include "config.h"
+#endif
 #include "../src/qasm.h"
 
 #if	id386
diff --git a/src/r_varsa.S b/src/r_varsa.S
index 91c20ff..ee7a5ff 100644
--- a/src/r_varsa.S
+++ b/src/r_varsa.S
@@ -2,6 +2,9 @@
 // r_varsa.s
 //
 
+#ifdef HAVE_CONFIG_H
+# include "config.h"
+#endif
 #include "../src/qasm.h"
 #include "d_ifacea.h"
 
diff --git a/src/snd_mixa.S b/src/snd_mixa.S
index 7128e19..6fce2c3 100644
--- a/src/snd_mixa.S
+++ b/src/snd_mixa.S
@@ -3,6 +3,9 @@
 // x86 assembly-language sound code
 //
 
+#ifdef HAVE_CONFIG_H
+# include "config.h"
+#endif
 #include "qasm.h"
 
 #if	id386
diff --git a/src/sys_dosa.S b/src/sys_dosa.S
index 755463a..f8012c6 100644
--- a/src/sys_dosa.S
+++ b/src/sys_dosa.S
@@ -2,6 +2,9 @@
 // sys_dosa.s
 // x86 assembly-language DOS-dependent routines.
 
+#ifdef HAVE_CONFIG_H
+# include "config.h"
+#endif
 #include "../src/qasm.h"