diff --git a/source/OctoVersion.Core/OctoVersionInfo.cs b/source/OctoVersion.Core/OctoVersionInfo.cs
index c13a99b..ea612fe 100644
--- a/source/OctoVersion.Core/OctoVersionInfo.cs
+++ b/source/OctoVersion.Core/OctoVersionInfo.cs
@@ -40,9 +40,19 @@ public OctoVersionInfo(SemanticVersion semanticVersion) : base(
     public string BuildMetadataWithPlus => string.IsNullOrWhiteSpace(BuildMetadata) ? string.Empty : $"+{InvalidBuildMetadataCharacters.Replace(BuildMetadata, "-")}";
     public string FullSemVer => $"{MajorMinorPatch}{PreReleaseTagWithDash}";
     public string InformationalVersion => $"{MajorMinorPatch}{PreReleaseTagWithDash}{BuildMetadataWithPlus}";
-    string NuGetCompatiblePreReleaseWithDash => PreReleaseTagWithDash.Substring(0, Math.Min(PreReleaseTagWithDash.Length, 20));
     public string NuGetVersion => $"{MajorMinorPatch}{NuGetCompatiblePreReleaseWithDash}";
 
+    string NuGetCompatiblePreReleaseWithDash
+    {
+        get
+        {
+            var truncated = PreReleaseTagWithDash.Substring(0, Math.Min(PreReleaseTagWithDash.Length, 20));
+
+            //a trailing dot is an empty pre-release identifier, which is not a valid version
+            return truncated.TrimEnd('.');
+        }
+    }
+
     public override string ToString()
     {
         return FullSemVer;
diff --git a/source/OctoVersion.Tests/WhenStringifyingAnOctoVersionInfo.cs b/source/OctoVersion.Tests/WhenStringifyingAnOctoVersionInfo.cs
index a15fc98..bdcb19a 100644
--- a/source/OctoVersion.Tests/WhenStringifyingAnOctoVersionInfo.cs
+++ b/source/OctoVersion.Tests/WhenStringifyingAnOctoVersionInfo.cs
@@ -44,6 +44,13 @@ public class WhenStringifyingAnOctoVersionInfo
         "dependabot/npm_and_yarn/source/TentacleArmy.Web/ini-1.3.6",
         "Branch.dependabot/npm_and_yarn/source/TentacleArmy.Web/ini-1.3.6.Sha.069392d9d2d37ddb6009998b92e70963badcc666");
 
+    //the NuGet-compatible pre-release is 20 characters, which lands this one exactly on a dot
+    static readonly OctoVersionInfo VersionWhereTheNuGetTruncationLandsOnADot = new(1,
+        1,
+        47,
+        "renovate-microsoft.aspnetcore.mvc.newtonsoftjson-10.x",
+        "Branch.renovate-microsoft.aspnetcore.mvc.newtonsoftjson-10.x.Sha.72529493c8ccfae2784cd604b7784294b03f388d");
+
     //xunit is blurgh - IEnumerable of object[]? ick.
     public static IEnumerable<object[]> PreReleaseTagWithDashTestCases()
     {
@@ -54,6 +61,7 @@ public static IEnumerable<object[]> PreReleaseTagWithDashTestCases()
         yield return new object[] { VersionWithPreReleaseTagAndBuildMetadata, "-pre", "it should append the pre-release tag, but not the build metadata" };
         yield return new object[] { VersionWithLongPreReleaseTagAndBuildMetadata, "-mark-genericDocumentStore", "it should add the pre-release tag, and ignore the build metadata" };
         yield return new object[] { VersionWithLongPreReleaseTagWithSlashesAndBuildMetadata, "-dependabot-npm-and-yarn-source-TentacleArmy.Web-ini-1.3.6", "it should add the pre-release tag, and ignore the build metadata" };
+        yield return new object[] { VersionWhereTheNuGetTruncationLandsOnADot, "-renovate-microsoft.aspnetcore.mvc.newtonsoftjson-10.x", "it should add the pre-release tag untruncated" };
     }
 
     [Theory]
@@ -108,6 +116,7 @@ public static IEnumerable<object[]> FullSemVerTestCases()
         yield return new object[] { VersionWithPreReleaseTagAndBuildMetadata, "1.2.3-pre", "it should return the major.minor.patch and pre-release but not the build metadata" };
         yield return new object[] { VersionWithLongPreReleaseTagAndBuildMetadata, "2021.1.3-mark-genericDocumentStore", "it should return the major.minor.patch and pre-release but not the build metadata" };
         yield return new object[] { VersionWithLongPreReleaseTagWithSlashesAndBuildMetadata, "2021.1.3-dependabot-npm-and-yarn-source-TentacleArmy.Web-ini-1.3.6", "it should return the major.minor.patch and pre-release but not the build metadata" };
+        yield return new object[] { VersionWhereTheNuGetTruncationLandsOnADot, "1.1.47-renovate-microsoft.aspnetcore.mvc.newtonsoftjson-10.x", "it should return the major.minor.patch and the untruncated pre-release" };
     }
 
     [Theory]
@@ -126,6 +135,7 @@ public static IEnumerable<object[]> NuGetVersionTestCases()
         yield return new object[] { VersionWithPreReleaseTagAndBuildMetadata, "1.2.3-pre", "it should return the major.minor.patch and pre-release but not the build metadata" };
         yield return new object[] { VersionWithLongPreReleaseTagAndBuildMetadata, "2021.1.3-mark-genericDocumen", "it should return the major.minor.patch and trim the pre-release to 20 chars" };
         yield return new object[] { VersionWithLongPreReleaseTagWithSlashesAndBuildMetadata, "2021.1.3-dependabot-npm-and-", "it should return the major.minor.patch and trim the pre-release to 20 chars" };
+        yield return new object[] { VersionWhereTheNuGetTruncationLandsOnADot, "1.1.47-renovate-microsoft", "a trimmed pre-release must not end with a dot" };
     }
 
     [Theory]
@@ -144,6 +154,7 @@ public static IEnumerable<object[]> InformationalVersionTestCases()
         yield return new object[] { VersionWithPreReleaseTagAndBuildMetadata, "1.2.3-pre+build", "it should return the major.minor.patch and pre-release and build metadata" };
         yield return new object[] { VersionWithLongPreReleaseTagAndBuildMetadata, "2021.1.3-mark-genericDocumentStore+Branch.mark-genericDocumentStore.Sha.fb13016f3a21d7c2058fb74ab25f19e5311c6550", "it should return the major.minor.patch and pre-release and build metadata" };
         yield return new object[] { VersionWithLongPreReleaseTagWithSlashesAndBuildMetadata, "2021.1.3-dependabot-npm-and-yarn-source-TentacleArmy.Web-ini-1.3.6+Branch.dependabot-npm-and-yarn-source-TentacleArmy.Web-ini-1.3.6.Sha.069392d9d2d37ddb6009998b92e70963badcc666", "it should return the major.minor.patch and pre-release and build metadata" };
+        yield return new object[] { VersionWhereTheNuGetTruncationLandsOnADot, "1.1.47-renovate-microsoft.aspnetcore.mvc.newtonsoftjson-10.x+Branch.renovate-microsoft.aspnetcore.mvc.newtonsoftjson-10.x.Sha.72529493c8ccfae2784cd604b7784294b03f388d", "it should return the major.minor.patch and pre-release and build metadata" };
     }
 
     [Theory]