diff --git a/Sources/TOMLDecoder/Parsing/Parser.swift b/Sources/TOMLDecoder/Parsing/Parser.swift
index 8b0d71a..e3da4d5 100644
--- a/Sources/TOMLDecoder/Parsing/Parser.swift
+++ b/Sources/TOMLDecoder/Parsing/Parser.swift
@@ -1343,6 +1343,9 @@ extension Token {
             }
             // Single zero is allowed to continue to the main loop
         }
+        guard index < text.upperBound else {
+            throw TOMLError(.invalidInteger(context: context, lineNumber: lineNumber, reason: "expected digit after base prefix"))
+        }
 
         while index < text.upperBound {
             let ch = bytes[index]
diff --git a/Tests/TOMLDecoderTests/TOMLTableKeyMembershipTests.swift b/Tests/TOMLDecoderTests/TOMLTableKeyMembershipTests.swift
index 7100229..64e4093 100644
--- a/Tests/TOMLDecoderTests/TOMLTableKeyMembershipTests.swift
+++ b/Tests/TOMLDecoderTests/TOMLTableKeyMembershipTests.swift
@@ -52,4 +52,11 @@ struct TOMLTableKeyMembershipTests {
             _ = try Dictionary(TOMLTable(source: "x = +\n"))
         }
     }
+
+    @Test
+    func basePrefixOnlyIntegerThrowsWithoutTrapping() throws {
+        #expect(throws: TOMLError.self) {
+            _ = try Dictionary(TOMLTable(source: "x = 0x\n"))
+        }
+    }
 }