diff --git a/tools/build/make_check/Makefile b/tools/build/make_check/Makefile
index a58f9ab72baa..d9c1847f6a95 100644
--- a/tools/build/make_check/Makefile
+++ b/tools/build/make_check/Makefile
@@ -59,6 +59,9 @@ all:
 	@echo "Running test plus_flag"
 	@${MAKE} plus_flag || ${MAKE} failure
 	@echo "PASS: Test plus_flag detected no regression."
+	@echo "Running test shell"
+	@! ${MAKE} shell >/dev/null 2>&1 && true || ${MAKE} failure
+	@echo "PASS: Test shell detected no regression."
 
 .if make(double)
 # Doubly-defined targets.  make(1) will warn, but use the "right" one.  If it
@@ -236,6 +239,13 @@ plus_flag_1:
 	+@cd /tmp; pwd
 .endif
 
+.if make(shell)
+# Test if make fully supports the .SHELL specification.
+.SHELL: path=/nonexistent
+A!= echo ok
+shell:
+.endif
+
 failure:
 	@echo "FAIL: Test failed: regression detected.  See above."
 	@false
diff --git a/tools/regression/usr.bin/make/Makefile b/tools/regression/usr.bin/make/Makefile
index a58f9ab72baa..d9c1847f6a95 100644
--- a/tools/regression/usr.bin/make/Makefile
+++ b/tools/regression/usr.bin/make/Makefile
@@ -59,6 +59,9 @@ all:
 	@echo "Running test plus_flag"
 	@${MAKE} plus_flag || ${MAKE} failure
 	@echo "PASS: Test plus_flag detected no regression."
+	@echo "Running test shell"
+	@! ${MAKE} shell >/dev/null 2>&1 && true || ${MAKE} failure
+	@echo "PASS: Test shell detected no regression."
 
 .if make(double)
 # Doubly-defined targets.  make(1) will warn, but use the "right" one.  If it
@@ -236,6 +239,13 @@ plus_flag_1:
 	+@cd /tmp; pwd
 .endif
 
+.if make(shell)
+# Test if make fully supports the .SHELL specification.
+.SHELL: path=/nonexistent
+A!= echo ok
+shell:
+.endif
+
 failure:
 	@echo "FAIL: Test failed: regression detected.  See above."
 	@false