diff --git a/README.rst b/README.rst
index 4fb4d81303..5f58b8cd11 100644
--- a/README.rst
+++ b/README.rst
@@ -89,7 +89,7 @@ possible.
 Development Site
 ================
 
-The current development version is 2.6.0a4. The current stable version is
+The current development version is 2.6.0b1. The current stable version is
 2.5.1. The `latest Cantera source code <https://github.com/Cantera/cantera>`_,
 the `issue tracker <https://github.com/Cantera/cantera/issues>`_ for bugs and
 enhancement requests, `downloads of Cantera releases and binary installers
diff --git a/SConstruct b/SConstruct
index a866b58d59..989bd3ae53 100644
--- a/SConstruct
+++ b/SConstruct
@@ -856,7 +856,7 @@ for arg in ARGUMENTS:
         logger.error(f"Encountered unexpected command line option: '{arg}'")
         sys.exit(1)
 
-env["cantera_version"] = "2.6.0a4"
+env["cantera_version"] = "2.6.0b1"
 # For use where pre-release tags are not permitted (MSI, sonames)
 env['cantera_pure_version'] = re.match(r'(\d+\.\d+\.\d+)', env['cantera_version']).group(0)
 env['cantera_short_version'] = re.match(r'(\d+\.\d+)', env['cantera_version']).group(0)
diff --git a/doc/doxygen/Doxyfile b/doc/doxygen/Doxyfile
index e53d7476c1..ebd204021a 100644
--- a/doc/doxygen/Doxyfile
+++ b/doc/doxygen/Doxyfile
@@ -38,7 +38,7 @@ PROJECT_NAME           = Cantera
 # could be handy for archiving the generated documentation or if some version
 # control system is used.
 
-PROJECT_NUMBER         = 2.6.0a4
+PROJECT_NUMBER         = 2.6.0b1
 
 # Using the PROJECT_BRIEF tag one can provide an optional one line description
 # for a project that appears at the top of each page and should give viewer a
diff --git a/interfaces/cython/cantera/ck2yaml.py b/interfaces/cython/cantera/ck2yaml.py
index 7afc90377b..7691f36be2 100644
--- a/interfaces/cython/cantera/ck2yaml.py
+++ b/interfaces/cython/cantera/ck2yaml.py
@@ -1900,10 +1900,10 @@ def write_yaml(self, name='gas', out_name='mech.yaml'):
             # Additional information regarding conversion
             files = [os.path.basename(f) for f in self.files]
             metadata = BlockMap([
-                ('generator', 'ck2yaml'),
-                ('input-files', FlowList(files)),
-                ('cantera-version', '2.6.0a4'),
-                ('date', formatdate(localtime=True)),
+                ("generator", "ck2yaml"),
+                ("input-files", FlowList(files)),
+                ("cantera-version", "2.6.0b1"),
+                ("date", formatdate(localtime=True)),
             ])
             if desc.strip():
                 metadata.yaml_set_comment_before_after_key('generator', before='\n')
diff --git a/interfaces/cython/cantera/cti2yaml.py b/interfaces/cython/cantera/cti2yaml.py
index 123008d522..a38c093f7e 100644
--- a/interfaces/cython/cantera/cti2yaml.py
+++ b/interfaces/cython/cantera/cti2yaml.py
@@ -1660,9 +1660,9 @@ def convert(filename=None, output_name=None, text=None, encoding="latin-1"):
 
         # information regarding conversion
         metadata = BlockMap([
-            ('generator', 'cti2yaml'),
-            ('cantera-version', '2.6.0a4'),
-            ('date', formatdate(localtime=True)),
+            ("generator", "cti2yaml"),
+            ("cantera-version", "2.6.0b1"),
+            ("date", formatdate(localtime=True)),
         ])
         if filename != "<string>":
             metadata['input-files'] = FlowList([base])
diff --git a/interfaces/cython/cantera/ctml2yaml.py b/interfaces/cython/cantera/ctml2yaml.py
index cf6fa5f18f..eae0a67c42 100644
--- a/interfaces/cython/cantera/ctml2yaml.py
+++ b/interfaces/cython/cantera/ctml2yaml.py
@@ -2641,7 +2641,7 @@ def convert(
     metadata = BlockMap(
         {
             "generator": "ctml2yaml",
-            "cantera-version": "2.6.0a4",
+            "cantera-version": "2.6.0b1",
             "date": formatdate(localtime=True),
         }
     )