diff --git a/s390x/Makefile b/s390x/Makefile
index ef8041a..7198882 100644
--- a/s390x/Makefile
+++ b/s390x/Makefile
@@ -24,6 +24,7 @@ tests += $(TEST_DIR)/mvpg.elf
 tests += $(TEST_DIR)/uv-host.elf
 tests += $(TEST_DIR)/edat.elf
 tests += $(TEST_DIR)/mvpg-sie.elf
+tests += $(TEST_DIR)/spec_ex-sie.elf
 
 tests_binary = $(patsubst %.elf,%.bin,$(tests))
 ifneq ($(HOST_KEY_DOCUMENT),)
@@ -85,6 +86,7 @@ snippet_asmlib = $(SNIPPET_DIR)/c/cstart.o
 # perquisites (=guests) for the snippet hosts.
 # $(TEST_DIR)/<snippet-host>.elf: snippets = $(SNIPPET_DIR)/<c/asm>/<snippet>.gbin
 $(TEST_DIR)/mvpg-sie.elf: snippets = $(SNIPPET_DIR)/c/mvpg-snippet.gbin
+$(TEST_DIR)/spec_ex-sie.elf: snippets = $(SNIPPET_DIR)/c/spec_ex.gbin
 
 $(SNIPPET_DIR)/asm/%.gbin: $(SNIPPET_DIR)/asm/%.o $(FLATLIBS)
 	$(OBJCOPY) -O binary $(patsubst %.gbin,%.o,$@) $@
diff --git a/lib/s390x/sie.h b/lib/s390x/sie.h
index ca514ef..7ef7251 100644
--- a/lib/s390x/sie.h
+++ b/lib/s390x/sie.h
@@ -98,6 +98,7 @@ struct kvm_s390_sie_block {
 	uint8_t		fpf;			/* 0x0060 */
 #define ECB_GS		0x40
 #define ECB_TE		0x10
+#define ECB_SPECI	0x08
 #define ECB_SRSI	0x04
 #define ECB_HOSTPROTINT	0x02
 	uint8_t		ecb;			/* 0x0061 */
diff --git a/s390x/snippets/c/spec_ex.c b/s390x/snippets/c/spec_ex.c
new file mode 100644
index 0000000..bdba4f4
--- /dev/null
+++ b/s390x/snippets/c/spec_ex.c
@@ -0,0 +1,20 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * © Copyright IBM Corp. 2021
+ *
+ * Snippet used by specification exception interception test.
+ */
+#include <stdint.h>
+#include <asm/arch_def.h>
+
+__attribute__((section(".text"))) int main(void)
+{
+	struct lowcore *lowcore = (struct lowcore *) 0;
+	uint64_t bad_psw = 0;
+
+	/* PSW bit 12 has no name or meaning and must be 0 */
+	lowcore->pgm_new_psw.mask = 1UL << (63 - 12);
+	lowcore->pgm_new_psw.addr = 0xdeadbeee;
+	asm volatile ("lpsw %0" :: "Q"(bad_psw));
+	return 0;
+}
diff --git a/s390x/spec_ex-sie.c b/s390x/spec_ex-sie.c
new file mode 100644
index 0000000..b7e79de
--- /dev/null
+++ b/s390x/spec_ex-sie.c
@@ -0,0 +1,83 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * © Copyright IBM Corp. 2021
+ *
+ * Specification exception interception test.
+ * Checks that specification exception interceptions occur as expected when
+ * specification exception interpretation is off/on.
+ */
+#include <libcflat.h>
+#include <sclp.h>
+#include <asm/page.h>
+#include <asm/arch_def.h>
+#include <alloc_page.h>
+#include <vm.h>
+#include <sie.h>
+
+static struct vm vm;
+extern const char _binary_s390x_snippets_c_spec_ex_gbin_start[];
+extern const char _binary_s390x_snippets_c_spec_ex_gbin_end[];
+
+static void setup_guest(void)
+{
+	char *guest;
+	int binary_size = ((uintptr_t)_binary_s390x_snippets_c_spec_ex_gbin_end -
+			   (uintptr_t)_binary_s390x_snippets_c_spec_ex_gbin_start);
+
+	setup_vm();
+	guest = alloc_pages(8);
+	memcpy(guest, _binary_s390x_snippets_c_spec_ex_gbin_start, binary_size);
+	sie_guest_create(&vm, (uint64_t) guest, HPAGE_SIZE);
+}
+
+static void reset_guest(void)
+{
+	vm.sblk->gpsw.addr = PAGE_SIZE * 4;
+	vm.sblk->gpsw.mask = PSW_MASK_64;
+	vm.sblk->icptcode = 0;
+}
+
+static void test_spec_ex_sie(void)
+{
+	setup_guest();
+
+	report_prefix_push("SIE spec ex interpretation");
+	report_prefix_push("off");
+	reset_guest();
+	sie(&vm);
+	/* interpretation off -> initial exception must cause interception */
+	report(vm.sblk->icptcode == ICPT_PROGI
+	       && vm.sblk->iprcc == PGM_INT_CODE_SPECIFICATION
+	       && vm.sblk->gpsw.addr != 0xdeadbeee,
+	       "Received specification exception intercept for initial exception");
+	report_prefix_pop();
+
+	report_prefix_push("on");
+	vm.sblk->ecb |= ECB_SPECI;
+	reset_guest();
+	sie(&vm);
+	/* interpretation on -> configuration dependent if initial exception causes
+	 * interception, but invalid new program PSW must
+	 */
+	report(vm.sblk->icptcode == ICPT_PROGI
+	       && vm.sblk->iprcc == PGM_INT_CODE_SPECIFICATION,
+	       "Received specification exception intercept");
+	if (vm.sblk->gpsw.addr == 0xdeadbeee)
+		report_info("Interpreted initial exception, intercepted invalid program new PSW exception");
+	else
+		report_info("Did not interpret initial exception");
+	report_prefix_pop();
+	report_prefix_pop();
+}
+
+int main(int argc, char **argv)
+{
+	if (!sclp_facilities.has_sief2) {
+		report_skip("SIEF2 facility unavailable");
+		goto out;
+	}
+
+	test_spec_ex_sie();
+out:
+	return report_summary();
+}
diff --git a/s390x/unittests.cfg b/s390x/unittests.cfg
index 9e1802f..3b454b7 100644
--- a/s390x/unittests.cfg
+++ b/s390x/unittests.cfg
@@ -109,3 +109,6 @@ file = edat.elf
 
 [mvpg-sie]
 file = mvpg-sie.elf
+
+[spec_ex-sie]
+file = spec_ex-sie.elf
