diff --git a/compiler/iface/FlagChecker.hs b/compiler/iface/FlagChecker.hs
index 92caee658bb16741a066f6d3601de9b2cfcee536..aac2c2499570c821917b0c7c055f6c34161037cc 100644
--- a/compiler/iface/FlagChecker.hs
+++ b/compiler/iface/FlagChecker.hs
@@ -61,7 +61,7 @@ fingerprintDynFlags dflags@DynFlags{..} this_mod nameio =
         ticky =
           map (`gopt` dflags) [Opt_Ticky, Opt_Ticky_Allocd, Opt_Ticky_LNE, Opt_Ticky_Dyn_Thunk]
 
-        flags = (mainis, safeHs, lang, cpp, paths, prof, ticky)
+        flags = ((mainis, safeHs, lang, cpp), (paths, prof, ticky, debugLevel))
 
     in -- pprTrace "flags" (ppr flags) $
        computeFingerprint nameio flags
diff --git a/testsuite/tests/driver/T17586/Makefile b/testsuite/tests/driver/T17586/Makefile
new file mode 100644
index 0000000000000000000000000000000000000000..ccca1f3c980bf43e0398ca703b953ff2dbdcc5bd
--- /dev/null
+++ b/testsuite/tests/driver/T17586/Makefile
@@ -0,0 +1,9 @@
+TOP=../..
+include $(TOP)/mk/boilerplate.mk
+include $(TOP)/mk/test.mk
+
+T17586:
+	"$(TEST_HC)" $(TEST_HC_OPTS) -o T17586 ./T17586.hs
+	./T17586
+	"$(TEST_HC)" $(TEST_HC_OPTS) -o T17586 ./T17586.hs -g3
+	./T17586
diff --git a/testsuite/tests/driver/T17586/T17586.hs b/testsuite/tests/driver/T17586/T17586.hs
new file mode 100644
index 0000000000000000000000000000000000000000..c81fb824375f7301b1e2cb394af79a654b519536
--- /dev/null
+++ b/testsuite/tests/driver/T17586/T17586.hs
@@ -0,0 +1,2 @@
+main :: IO ()
+main = putStrLn "hello world"
diff --git a/testsuite/tests/driver/T17586/T17586.stdout b/testsuite/tests/driver/T17586/T17586.stdout
new file mode 100644
index 0000000000000000000000000000000000000000..86972772517bdd0761c856b823c8371e4755dc30
--- /dev/null
+++ b/testsuite/tests/driver/T17586/T17586.stdout
@@ -0,0 +1,6 @@
+[1 of 1] Compiling Main             ( T17586.hs, T17586.o )
+Linking T17586 ...
+hello world
+[1 of 1] Compiling Main             ( T17586.hs, T17586.o ) [flags changed]
+Linking T17586 ...
+hello world
diff --git a/testsuite/tests/driver/T17586/all.T b/testsuite/tests/driver/T17586/all.T
new file mode 100644
index 0000000000000000000000000000000000000000..2ec89b4d03a0567c0dad4f5535f2ced91787a209
--- /dev/null
+++ b/testsuite/tests/driver/T17586/all.T
@@ -0,0 +1 @@
+test('T17586', normal, makefile_test, [])