diff --git a/lib/Demangling/NodePrinter.cpp b/lib/Demangling/NodePrinter.cpp
index 5949749c4ab5b..65d140dab80e5 100644
--- a/lib/Demangling/NodePrinter.cpp
+++ b/lib/Demangling/NodePrinter.cpp
@@ -3407,6 +3407,11 @@ std::string Demangle::keyPathSourceString(const char *MangledName,
       case Node::Kind::Subscript: {
         std::string subscriptText = "subscript(";
         std::vector<std::string> argumentTypeNames;
+        auto getArgumentTypeName = [&argumentTypeNames](size_t i) {
+          if (i < argumentTypeNames.size())
+            return argumentTypeNames[i];
+          return std::string("<unknown>");
+        };
         // Multiple arguments case
         NodePointer argList = matchSequenceOfKinds(
             child, {
@@ -3454,27 +3459,27 @@ std::string Demangle::keyPathSourceString(const char *MangledName,
           if (child->getKind() == Node::Kind::LabelList) {
             size_t numChildren = child->getNumChildren();
             if (numChildren == 0) {
-              subscriptText += unlabelledArg + argumentTypeNames[0];
+              subscriptText += unlabelledArg + getArgumentTypeName(0);
             } else {
               while (idx < numChildren) {
                 Node *argChild = child->getChild(idx);
                 idx += 1;
                 if (argChild->getKind() == Node::Kind::Identifier) {
                   subscriptText += std::string(argChild->getText()) + ": " +
-                                   argumentTypeNames[idx - 1];
+                                   getArgumentTypeName(idx - 1);
                   if (idx != numChildren) {
                     subscriptText += ", ";
                   }
                 } else if (argChild->getKind() ==
                                Node::Kind::FirstElementMarker ||
                            argChild->getKind() == Node::Kind::VariadicMarker) {
-                  subscriptText += unlabelledArg + argumentTypeNames[idx - 1];
+                  subscriptText += unlabelledArg + getArgumentTypeName(idx - 1);
                 }
               }
             }
           }
         } else {
-          subscriptText += unlabelledArg + argumentTypeNames[0];
+          subscriptText += unlabelledArg + getArgumentTypeName(0);
         }
         return subscriptText + ")";
       }
diff --git a/test/Interpreter/keypath.swift b/test/Interpreter/keypath.swift
index 6250d2792ea69..e4205980e21bc 100644
--- a/test/Interpreter/keypath.swift
+++ b/test/Interpreter/keypath.swift
@@ -36,6 +36,21 @@ class Controller {
     0
   }
   
+  subscript<T>(array: [T]) -> T? {
+    array.first
+  }
+
+  subscript<T, U>(array: [T], array2: [U]) -> T? {
+    array.first
+  }
+
+  subscript<T>(array array: [T]) -> T? {
+    array.first
+  }
+
+  subscript<T, U>(array array: [T], array2 array2: [U]) -> T? {
+    array.first
+  }
 }
 
 struct S {
@@ -95,3 +110,14 @@ print(\Controller.thirdLabel)
 print(\Controller.[])
 // CHECK: \Controller.self
 print(\Controller.self)
+
+// Subscripts with dependent generic types don't produce good output currently,
+// so we're just checking to make sure they don't crash.
+// CHECK: \Controller.
+print(\Controller[[42]])
+// CHECK: Controller.
+print(\Controller[[42], [42]])
+// CHECK: \Controller.
+print(\Controller[array: [42]])
+// CHECK: \Controller.
+print(\Controller[array: [42], array2: [42]])
diff --git a/test/stdlib/symbol-visibility-linux.test-sh b/test/stdlib/symbol-visibility-linux.test-sh
index d923230f4db1a..98edf6ee404f9 100644
--- a/test/stdlib/symbol-visibility-linux.test-sh
+++ b/test/stdlib/symbol-visibility-linux.test-sh
@@ -37,6 +37,7 @@
 // RUN:             -e  _ZSt9call_onceIRFvPvEJDnEEvRSt9once_flagOT_DpOT0_ \
 // RUN:             -e _ZNKSt8functionIFSsmmEEclEmm \
 // RUN:             -e _ZNSt6vectorINSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEESaIS5_EE17_M_realloc_insertIJS5_EEEvN9__gnu_cxx17__normal_iteratorIPS5_S7_EEDpOT_ \
+// RUN:             -e _ZStplIcSt11char_traitsIcESaIcEENSt7__cxx1112basic_stringIT_T0_T1_EERKS8_OS8_ \
 // RUN:             -e _ZStplIcSt11char_traitsIcESaIcEENSt7__cxx1112basic_stringIT_T0_T1_EERKS8_SA_ \
 // RUN:   > %t/swiftCore-all.txt
 // RUN: %llvm-nm --defined-only --extern-only --no-weak %platform-dylib-dir/%target-library-name(swiftCore) > %t/swiftCore-no-weak.txt
@@ -67,6 +68,7 @@
 // RUN:             -e  _ZSt9call_onceIRFvPvEJDnEEvRSt9once_flagOT_DpOT0_ \
 // RUN:             -e _ZNKSt8functionIFSsmmEEclEmm \
 // RUN:             -e _ZNSt6vectorINSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEESaIS5_EE17_M_realloc_insertIJS5_EEEvN9__gnu_cxx17__normal_iteratorIPS5_S7_EEDpOT_ \
+// RUN:             -e _ZStplIcSt11char_traitsIcESaIcEENSt7__cxx1112basic_stringIT_T0_T1_EERKS8_OS8_ \
 // RUN:             -e _ZStplIcSt11char_traitsIcESaIcEENSt7__cxx1112basic_stringIT_T0_T1_EERKS8_SA_ \
 // RUN:   > %t/swiftRemoteMirror-all.txt
 // RUN: %llvm-nm --defined-only --extern-only --no-weak %platform-dylib-dir/%target-library-name(swiftRemoteMirror) > %t/swiftRemoteMirror-no-weak.txt