diff --git a/tools/tracing/rtla/Makefile b/tools/tracing/rtla/Makefile
index 60a102538988..387bc6cc18f0 100644
--- a/tools/tracing/rtla/Makefile
+++ b/tools/tracing/rtla/Makefile
@@ -45,6 +45,9 @@ else
   LIB_OUTPUT = $(CURDIR)/lib
 endif
 
+LIB_CTYPE = $(LIB_OUTPUT)/ctype.o
+LIB_CTYPE_SRC = $(srctree)/tools/lib/ctype.c
+
 LIB_STRING = $(LIB_OUTPUT)/string.o
 LIB_STRING_SRC = $(srctree)/tools/lib/string.c
 
@@ -117,12 +120,12 @@ tests/bpf/bpf_action_map.o: tests/bpf/bpf_action_map.c
 	$(Q)echo "BPF skeleton support is disabled, skipping tests/bpf/bpf_action_map.o"
 endif
 
-$(RTLA): $(RTLA_IN) $(LIBSUBCMD) $(LIB_STRING) $(LIB_STR_ERROR_R)
-	$(QUIET_LINK)$(CC) $(LDFLAGS) -o $(RTLA) $(RTLA_IN) $(LIBSUBCMD) $(LIB_STRING) $(LIB_STR_ERROR_R) $(EXTLIBS)
+$(RTLA): $(RTLA_IN) $(LIBSUBCMD) $(LIB_CTYPE) $(LIB_STRING) $(LIB_STR_ERROR_R)
+	$(QUIET_LINK)$(CC) $(LDFLAGS) -o $(RTLA) $(RTLA_IN) $(LIBSUBCMD) $(LIB_CTYPE) $(LIB_STRING) $(LIB_STR_ERROR_R) $(EXTLIBS)
 
-static: $(RTLA_IN) $(LIBSUBCMD) $(LIB_STRING) $(LIB_STR_ERROR_R)
+static: $(RTLA_IN) $(LIBSUBCMD) $(LIB_CTYPE) $(LIB_STRING) $(LIB_STR_ERROR_R)
 	$(eval LDFLAGS += -static)
-	$(QUIET_LINK)$(CC) -static $(LDFLAGS) -o $(RTLA)-static $(RTLA_IN) $(LIBSUBCMD) $(LIB_STRING) $(LIB_STR_ERROR_R) $(EXTLIBS)
+	$(QUIET_LINK)$(CC) -static $(LDFLAGS) -o $(RTLA)-static $(RTLA_IN) $(LIBSUBCMD) $(LIB_CTYPE) $(LIB_STRING) $(LIB_STR_ERROR_R) $(EXTLIBS)
 
 rtla.%: fixdep FORCE
 	make -f $(srctree)/tools/build/Makefile.build dir=. $@
@@ -150,6 +153,9 @@ $(LIB_STR_ERROR_R): $(LIB_STR_ERROR_R_SRC) | $(LIB_OUTPUT)
 $(LIB_STRING): $(LIB_STRING_SRC) | $(LIB_OUTPUT)
 	$(QUIET_CC)$(CC) $(CFLAGS) -c -o $@ $<
 
+$(LIB_CTYPE): $(LIB_CTYPE_SRC) | $(LIB_OUTPUT)
+	$(QUIET_CC)$(CC) $(CFLAGS) -c -o $@ $<
+
 libsubcmd-clean:
 	$(call QUIET_CLEAN, libsubcmd)
 	$(Q)$(RM) -r -- $(LIBSUBCMD_OUTPUT)
diff --git a/tools/tracing/rtla/src/common.c b/tools/tracing/rtla/src/common.c
index d0a8a6edbf0c..8c7f5e75b2ec 100644
--- a/tools/tracing/rtla/src/common.c
+++ b/tools/tracing/rtla/src/common.c
@@ -5,6 +5,7 @@
 #include <signal.h>
 #include <stdlib.h>
 #include <string.h>
+#include <unistd.h>
 #include <sys/sysinfo.h>
 
 #include "common.h"