diff --git a/compiler/sighashes.nim b/compiler/sighashes.nim
index aac97cdf33..67cd6e1b28 100644
--- a/compiler/sighashes.nim
+++ b/compiler/sighashes.nim
@@ -143,7 +143,11 @@ proc hashType(c: var MD5Context, t: PType; flags: set[ConsiderFlag]; conf: Confi
     # backend spelling instead of collapsing into the generic Nim builtin:
     c &= char(t.kind)
     if t.sym != nil and {sfImportc, sfExportc} * t.sym.flags != {}:
-      c.hashSym(t.sym)
+      # Aliases inherit the external name, but have a different symbol.
+      if t.sym.loc.snippet != "":
+        c &= t.sym.loc.snippet
+      else:
+        c.hashSym(t.sym)
   of tyObject, tyEnum:
     if t.typeInst != nil:
       # prevent against infinite recursions here, see bug #8883:
diff --git a/tests/ccgbugs/mseq_importc_alias.nim b/tests/ccgbugs/mseq_importc_alias.nim
new file mode 100644
index 0000000000..5b3f97747d
--- /dev/null
+++ b/tests/ccgbugs/mseq_importc_alias.nim
@@ -0,0 +1,5 @@
+proc resizeCints*(s: var seq[cint], n: int) =
+  s.setLen(n)
+
+proc cintLen*(s: seq[cint]): int =
+  result = s.len
diff --git a/tests/ccgbugs/tseq_importc_alias_crossmod.nim b/tests/ccgbugs/tseq_importc_alias_crossmod.nim
new file mode 100644
index 0000000000..a4c94d2b2e
--- /dev/null
+++ b/tests/ccgbugs/tseq_importc_alias_crossmod.nim
@@ -0,0 +1,15 @@
+discard """
+  action: run
+  targets: "c cpp"
+"""
+
+import mseq_importc_alias
+
+type CIntAlias = cint
+
+var fds: seq[CIntAlias]
+doAssert cintLen(@[1.cint, 2.cint]) == 2
+doAssert cintLen(fds) == 0
+resizeCints(fds, 3)
+fds[1] = CIntAlias(7)
+doAssert cintLen(fds) == 3
diff --git a/tests/ccgbugs/tseq_importc_alias_mangle.nim b/tests/ccgbugs/tseq_importc_alias_mangle.nim
new file mode 100644
index 0000000000..a6a9074ec4
--- /dev/null
+++ b/tests/ccgbugs/tseq_importc_alias_mangle.nim
@@ -0,0 +1,20 @@
+discard """
+  action: run
+  targets: "c cpp"
+"""
+
+type CIntAlias = cint
+
+var x: (cint,) = (1.cint,)
+var y: (CIntAlias,) = x
+x = y
+doAssert x[0] == 1.cint
+
+var a: seq[cint]
+var b: seq[CIntAlias]
+a.add 1.cint
+a.add 2.cint
+b = a
+a = b
+doAssert a[0] == 1.cint
+doAssert b[1] == CIntAlias(2)
diff --git a/tests/ic/timportcalias.nim b/tests/ic/timportcalias.nim
new file mode 100644
index 0000000000..2f6c20f4b5
--- /dev/null
+++ b/tests/ic/timportcalias.nim
@@ -0,0 +1,7 @@
+import ../ccgbugs/mseq_importc_alias
+
+type CIntAlias = cint
+
+var values: seq[CIntAlias]
+resizeCints(values, 2)
+doAssert cintLen(values) == 2