diff --git a/Doxyfile b/Doxyfile
index 6eee6a5..859a740 100644
--- a/Doxyfile
+++ b/Doxyfile
@@ -5,5 +5,5 @@ INPUT = libndt.hpp
 JAVADOC_AUTOBRIEF = YES
 PROJECT_BRIEF = "Measurement Kit NDT library"
 PROJECT_NAME = measurement-kit/libndt
-PROJECT_NUMBER = v0.26.0
+PROJECT_NUMBER = v0.25.1
 RECURSIVE = NO
diff --git a/libndt.hpp b/libndt.hpp
index 7ea7eb4..b616703 100644
--- a/libndt.hpp
+++ b/libndt.hpp
@@ -57,10 +57,10 @@ using Version = unsigned int;
 constexpr Version version_major = Version{0};
 
 /// Minor API version number of measurement-kit/libndt.
-constexpr Version version_minor = Version{26};
+constexpr Version version_minor = Version{25};
 
 /// Patch API version number of measurement-kit/libndt.
-constexpr Version version_patch = Version{0};
+constexpr Version version_patch = Version{1};
 
 /// Flags that indicate what subtests to run.
 using NettestFlags = unsigned char;