diff --git a/Makefile b/Makefile
index 94d0b78..4fd60c5 100644
--- a/Makefile
+++ b/Makefile
@@ -32,7 +32,7 @@ RUSTLIBS = --extern getopt=build/o/libgetopt.rlib \
 CFLAGS += -I$(SYSEXITS)
 
 .PHONY: all
-all: dj false fop hru intcmp mm npc rpn scrut str strcmp swab true
+all: dj false fop hru intcmp mm npc rpn simexec scrut str strcmp swab true
 
 # keep build/include until bindgen(1) has stdin support
 # https://github.com/rust-lang/rust-bindgen/issues/2703
@@ -132,6 +132,11 @@ scrut: build/bin/scrut
 build/bin/scrut: src/scrut.c build
 	$(CC) $(CFLAGS) -o $@ src/scrut.c
 
+.PHONY: simexec
+simexec: build/bin/simexec
+build/bin/simexec: src/simexec.c build
+	$(CC) $(CFLAGS) -o $@ src/simexec.c
+
 .PHONY: str
 str: build/bin/str
 build/bin/str: src/str.c build