diff --git a/lib/libsys/Makefile b/lib/libsys/Makefile
index 4c9923d70..1ba8c4f29 100644
--- a/lib/libsys/Makefile
+++ b/lib/libsys/Makefile
@@ -13,7 +13,6 @@ SRCS=  \
 	env_parse.c \
 	env_prefix.c \
 	fkey_ctl.c \
-	gcov.c \
 	get_randomness.c \
 	getidle.c \
 	getsysinfo.c \
@@ -50,7 +49,6 @@ SRCS=  \
 	sched_start.c \
 	sched_stop.c \
 	sef.c \
-	sef_gcov.c \
 	sef_init.c \
 	sef_liveupdate.c \
 	sef_ping.c \
@@ -128,6 +126,11 @@ SRCS=  \
 	vm_yield_get_block.c \
 	vprintf.c \
 
+.if ${MKCOVERAGE} != "no"
+SRCS+=	gcov.c \
+	sef_gcov.c
+CPPFLAGS+= -DUSE_COVERAGE
+.endif
 
 CPPFLAGS.sched_start.c+=	-I${MINIXSRCDIR}
 
diff --git a/lib/libsys/sef.c b/lib/libsys/sef.c
index 796da4c18..400058b7a 100644
--- a/lib/libsys/sef.c
+++ b/lib/libsys/sef.c
@@ -24,7 +24,9 @@ FORWARD _PROTOTYPE( void sef_debug_refresh_params, (void) );
 PUBLIC _PROTOTYPE( char* sef_debug_header, (void) );
 
 /* SEF Init prototypes. */
+#ifdef USE_COVERAGE
 EXTERN _PROTOTYPE( int do_sef_gcov_request, (message *m_ptr) );
+#endif
 EXTERN _PROTOTYPE( int do_sef_rs_init, (endpoint_t old_endpoint) );
 EXTERN _PROTOTYPE( int do_sef_init_request, (message *m_ptr) );
 
@@ -155,6 +157,7 @@ PUBLIC int sef_receive_status(endpoint_t src, message *m_ptr, int *status_ptr)
       }
 #endif
 
+#ifdef USE_COVERAGE
       /* Intercept GCOV data requests (sent by VFS in vfs/gcov.c). */
       if(m_ptr->m_type == COMMON_REQ_GCOV_DATA &&
 	 m_ptr->m_source == VFS_PROC_NR) {
@@ -162,6 +165,7 @@ PUBLIC int sef_receive_status(endpoint_t src, message *m_ptr, int *status_ptr)
               continue;
           }
       }
+#endif
 
       /* If we get this far, this is not a valid SEF request, return and
        * let the caller deal with that.
diff --git a/lib/nbsd_libminlib/Makefile b/lib/nbsd_libminlib/Makefile
index 12bbfc39c..0e599a0af 100644
--- a/lib/nbsd_libminlib/Makefile
+++ b/lib/nbsd_libminlib/Makefile
@@ -11,7 +11,9 @@ SRCS+= 	fslib.c fsversion.c
 SRCS+= dhcp_gettag.c dhcp_settag.c
 
 # Gcov support.
+.if ${MKCOVERAGE} != "no"
 SRCS+= gcov.c gcov_flush.c
+.endif
 
 # Various utils
 SRCS+= itoa.c u64util.c
diff --git a/servers/vfs/Makefile b/servers/vfs/Makefile
index dfe9d197d..a3f08d01a 100644
--- a/servers/vfs/Makefile
+++ b/servers/vfs/Makefile
@@ -1,10 +1,17 @@
 # Makefile for Virtual File System (VFS)
+.include <bsd.own.mk>
+
 PROG=	vfs
 SRCS=	main.c open.c read.c write.c pipe.c dmap.c \
 	path.c device.c mount.c link.c exec.c \
 	filedes.c stadir.c protect.c time.c \
 	lock.c misc.c utility.c select.c table.c \
-	vnode.c vmnt.c request.c fscall.c gcov.c
+	vnode.c vmnt.c request.c fscall.c
+
+.if ${MKCOVERAGE} != "no"
+SRCS+=	gcov.c
+CPPFLAGS+= -DUSE_COVERAGE
+.endif
 
 DPADD+=	${LIBSYS} ${LIBTIMERS} ${LIBEXEC}
 LDADD+=	-lsys -ltimers -lexec
diff --git a/servers/vfs/proto.h b/servers/vfs/proto.h
index be51cdc9d..e54810f12 100644
--- a/servers/vfs/proto.h
+++ b/servers/vfs/proto.h
@@ -282,6 +282,9 @@ _PROTOTYPE( int do_write, (void)					);
 
 /* gcov.c */
 _PROTOTYPE( int do_gcov_flush, (void)					);
+#if ! USE_COVERAGE
+#define do_gcov_flush no_sys
+#endif
 
 /* select.c */
 _PROTOTYPE( int do_select, (void)					);
diff --git a/share/mk/bsd.own.mk b/share/mk/bsd.own.mk
index b945b4fcf..3c97108e9 100644
--- a/share/mk/bsd.own.mk
+++ b/share/mk/bsd.own.mk
@@ -821,6 +821,7 @@ MKWATCHDOG:=	no
 MKACPI:=	no
 MKAPIC:=	no
 MKMCONTEXT:=	no
+MKCOVERAGE:=	no
 .endif
 
 #