diff --git a/doc/manual/pdfmorph.pdf b/doc/manual/pdfmorph.pdf
index 7ea99f6b..06e470ca 100644
Binary files a/doc/manual/pdfmorph.pdf and b/doc/manual/pdfmorph.pdf differ
diff --git a/doc/manual/pdfmorph.texinfo b/doc/manual/pdfmorph.texinfo
index c7c69b08..7239202c 100644
--- a/doc/manual/pdfmorph.texinfo
+++ b/doc/manual/pdfmorph.texinfo
@@ -728,7 +728,7 @@ and the nanoparticle form function is scaled
 Finally, we can conclude that the PDF after expansion follows
 @displaymath
 G'(r) = {{R(r/\alpha)} \over {\alpha r}} - 4\pi r {{\rho_0} \over {\alpha^3}} \gamma_0(r / \alpha)
-= {{G(\alpha r)} \over \alpha^2},
+= {{G(r/\alpha)} \over \alpha^2},
 @end displaymath
 which is the original PDF scaled by a factor @math{1/\alpha^2} and stretched by @math{\alpha}.
 
diff --git a/news/error_fixes.rst b/news/error_fixes.rst
new file mode 100644
index 00000000..e47f6677
--- /dev/null
+++ b/news/error_fixes.rst
@@ -0,0 +1,23 @@
+**Added:**
+
+* <news item>
+
+**Changed:**
+
+* <news item>
+
+**Deprecated:**
+
+* <news item>
+
+**Removed:**
+
+* <news item>
+
+**Fixed:**
+
+* Mathematical error in manual
+
+**Security:**
+
+* <news item>
diff --git a/tutorial/PDFmorph_manual.pdf b/tutorial/PDFmorph_manual.pdf
index 7ea99f6b..7239202c 100644
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