diff --git a/src/buildPronoun.js b/src/buildPronoun.js
index 9127a3358..acfaa89e9 100644
--- a/src/buildPronoun.js
+++ b/src/buildPronoun.js
@@ -59,7 +59,7 @@ const buildPronounFromTemplate = (key, template) => {
 };
 
 const buildPronounFromSlashes = (config, path) => {
-    const chunks = path.split(/(?<!`)\//).filter((s) => !!s);
+    const chunks = path.split(/(?<!`)\//);
     let plural = false;
     let pluralHonorific = false;
     let description = '';
@@ -77,7 +77,13 @@ const buildPronounFromSlashes = (config, path) => {
                 }
             }
         } else {
-            morphemeChunks.push(unescapeControlSymbols(chunk));
+            if (chunk === '~') {
+                morphemeChunks.push(null);
+            } else if (chunk === ' ') {
+                morphemeChunks.push('');
+            } else {
+                morphemeChunks.push(unescapeControlSymbols(chunk));
+            }
         }
     }
     if (description.length > Pronoun.DESCRIPTION_MAXLENGTH) {
diff --git a/src/classes.js b/src/classes.js
index 10ebfc341..baaf6fb63 100644
--- a/src/classes.js
+++ b/src/classes.js
@@ -478,7 +478,16 @@ export class Pronoun {
         } else {
             chunks = Object.values(this.morphemes);
         }
-        chunks = chunks.map(escapeControlSymbols);
+        chunks = chunks.map((chunk) => {
+            if (chunk === null) {
+                return '~';
+            } else if (chunk === '') {
+                // use an extra space because double slashes get replaced by a single one during a request
+                return ' ';
+            } else {
+                return escapeControlSymbols(chunk);
+            }
+        });
 
         if (this.plural[0]) {
             chunks.push(':plural');
@@ -490,7 +499,8 @@ export class Pronoun {
             chunks.push(`:description=${escapeControlSymbols(this.description)}`);
         }
 
-        return chunks.join('/');
+        // encode a trailing space so that it does not get removed during a request
+        return chunks.join('/').replace(/ $/, encodeURI(' '));
     }
 
     static from(data) {
diff --git a/src/helpers.js b/src/helpers.js
index dfbfaafdb..6694587b2 100644
--- a/src/helpers.js
+++ b/src/helpers.js
@@ -269,12 +269,18 @@ const escapeChars = {
 export const escapeHtml = (text) => text.replace(/[&<>"]/g, (tag) => escapeChars[tag] || tag);
 
 export const escapeControlSymbols = (text) => {
+    if (text === null) {
+        return null;
+    }
     // a backtick is used because browsers replace backslashes
     // with forward slashes if they are not url-encoded
     return text.replaceAll(/[`&/|,]/g, '`$&');
 };
 
 export const unescapeControlSymbols = (text) => {
+    if (text === null) {
+        return null;
+    }
     return text.replaceAll(/`(.)/g, '$1');
 };
 
diff --git a/test/buildPronoun.test.js b/test/buildPronoun.test.js
index 38a17d842..20291328b 100644
--- a/test/buildPronoun.test.js
+++ b/test/buildPronoun.test.js
@@ -162,6 +162,21 @@ describe('when configured that slashes contain all morphemes', () => {
         actual.toBeDefined();
         actual.toEqual(generatedPronouns.aerPluralWithDescription);
     });
+    test('builds generated pronoun with some morphemes empty', () => {
+        const actual = expect(buildPronoun(pronouns, 'ae/aer/aer/ /aerself'));
+        actual.toBeDefined();
+        actual.toEqual(generatedPronouns.aerWithEmptyPossessivePronoun);
+    });
+    test('builds generated pronoun with morpheme at end empty', () => {
+        const actual = expect(buildPronoun(pronouns, 'ae/aer/aer/aers/'));
+        actual.toBeDefined();
+        actual.toEqual(generatedPronouns.aerWithEmptyReflexive);
+    });
+    test('builds generated pronoun with some morphemes unset', () => {
+        const actual = expect(buildPronoun(pronouns, 'ae/aer/aer/~/aerself'));
+        actual.toBeDefined();
+        actual.toEqual(generatedPronouns.aerWithUnsetPossessivePronoun);
+    });
     test('builds nothing if morphemes are missing', () => {
         expect(buildPronoun(pronouns, 'ae/aer/aer/aerself')).toBeUndefined();
     });
diff --git a/test/classes.test.js b/test/classes.test.js
index 936a55e70..2f876f071 100644
--- a/test/classes.test.js
+++ b/test/classes.test.js
@@ -56,6 +56,18 @@ describe('formatting a pronoun with slashes', () => {
             expect(generatedPronouns.sSlashHe.toStringSlashes())
                 .toEqual('s`/he/hir/hir/hirs/hirself');
         });
+        test('empty morphemes receive space as placeholder', () => {
+            expect(generatedPronouns.aerWithEmptyPossessivePronoun.toStringSlashes())
+                .toEqual('ae/aer/aer/ /aerself');
+        });
+        test('empty morphemes at end receive url-encoded space as placeholder', () => {
+            expect(generatedPronouns.aerWithEmptyReflexive.toStringSlashes())
+                .toEqual('ae/aer/aer/aers/%20');
+        });
+        test('unset morphemes receive tilde as placeholder', () => {
+            expect(generatedPronouns.aerWithUnsetPossessivePronoun.toStringSlashes())
+                .toEqual('ae/aer/aer/~/aerself');
+        });
         test('adds plural modifier if necessary', () => {
             expect(generatedPronouns.aerPlural.toStringSlashes())
                 .toEqual('ae/aer/aer/aers/aerselves/:plural');
diff --git a/test/fixtures/pronouns.js b/test/fixtures/pronouns.js
index 284b688fe..9009f0ca5 100644
--- a/test/fixtures/pronouns.js
+++ b/test/fixtures/pronouns.js
@@ -164,6 +164,23 @@ const aerWithEmptyPossessivePronoun = new Pronoun(
     '__generator__',
     false,
 );
+const aerWithEmptyReflexive = new Pronoun(
+    'ae/aer',
+    '',
+    false,
+    {
+        pronoun_subject: 'ae',
+        pronoun_object: 'aer',
+        possessive_determiner: 'aer',
+        possessive_pronoun: 'aers',
+        reflexive: '',
+    },
+    [false],
+    [false],
+    [],
+    '__generator__',
+    false,
+);
 const aerWithUnsetPossessivePronoun = new Pronoun(
     'ae/aer',
     '',
@@ -207,6 +224,7 @@ export const generated = {
     aerWithDescription,
     aerPluralWithDescription,
     aerWithEmptyPossessivePronoun,
+    aerWithEmptyReflexive,
     aerWithUnsetPossessivePronoun,
     sSlashHe,
 };
diff --git a/test/helpers.test.js b/test/helpers.test.js
index 232d48c1f..7d00ed895 100644
--- a/test/helpers.test.js
+++ b/test/helpers.test.js
@@ -36,12 +36,18 @@ const controlSymbols = [
 ];
 
 describe('when escaping control symbols', () => {
+    test('safely handles null', () => {
+        expect(escapeControlSymbols(null)).toBeNull();
+    });
     test.each(controlSymbols)('$description get escaped with `', ({ unescaped, escaped }) => {
         expect(escapeControlSymbols(unescaped)).toBe(escaped);
     });
 });
 
 describe('when unescaping control symbols', () => {
+    test('safely handles null', () => {
+        expect(unescapeControlSymbols(null)).toBeNull();
+    });
     test.each(controlSymbols)('$description get unescaped', ({ unescaped, escaped }) => {
         expect(unescapeControlSymbols(escaped)).toBe(unescaped);
     });